I started a separate thread hoping to get directly to what I need. But didn't get any responses. And I need to decide by Monday the latest. I have printed this whole thread over 300 pages and about a 1/3 of the way through. And as it seems that alot a very knowledgeable people monitor this particular thread, please help.

Thanks


For my situation, what is better Green Glue or RSIC clips?

The structure is basically built. What I have is the theater room on the first floor and bedroom right on top. The room size is 14’ 2” x 30’. At this time I’m not thinking of the 3 outer walls. But the wall adjoining the house is my old exterior with the siding removed. So it consists of thick wood planks and paneling attached to the internal studs. After some discussions with my architect and contractor I do believe it is in my best interest to leave it as is. I could just attach sheetrock right to it with no problem except for what I perceive will be sound problems.
Originally I was thinking of using RSIC clips attached to the old wall then sheetrock to the channels. The ceiling is just standard 16” O.C. joists with wood boards above. And here I was also thinking of using RSIC clips, fiberglass insulation and such. However while working on a supply list based on manufacture recommendations I figured I needed a little over 200 clips which came to a cost of about $1000 (Ouch) before even adding the price of sheetrock and channel strips. That is just more then I can afford to spend right now.
I have been hearing amazing things about Green Glue around here. Now in general is Green Glue better then the RSIC clip solution? Or is it application specific? I can afford to put clips on the side wall just to lift the sheetrock off of the flat surface of the house. As well as give me a little room to run electrical wires along the wall. But on the ceiling will fiberglass, double sheetrock and Green Glue give me the results I need? It doesn’t have to be soundproof but some control would be really nice.

Any other recommendations and thoughts would also be greatly appreciated.

Check out this page:

http://www.thegreengluecompany.com/usingGreenGlue.php

Near the bottom, it talks about different ceiling construction methods. I think, in general, mechanical decoupling (RSIC clips) is going to be better than GreenGlue. But if you can't afford using clips on the ceiling, you go to next best, which is a GreenGlue sandwich.

Orlando,

PAC clips are a fantastic product. Very effective to decouple surfaces. They are particularly effective on ceilings where de-coupling is so needed. There are not many ways to decouple a ceiling.

Regarding your walls, maybe consider modifying those walls into staggered stud walls. http://www.greengluecompany.com/wallTypes.php

This adds only an inch of depth to the existing walls.

It's easy and cheap and super effective. Then they're decoupled. Insulate and drywall and you're good to go.

Thanks for the info guys.

My room is alot narrower then I wanted but there was noting that could be done.

Ted - I also can't do anything to the side wall. It is what it is and is not going to change. The only way to get to the stud would be to start disassembling part of my existing house. Which is why the contractor and architect were in agreement to touch nothing. If I add a stud then it will take away some very valuable inches.

I would love to go clips in the ceiling but based on recommendations I would need 145 of them which gets me to close to 800 without channels and dry wall. I just can't afford to go that high out the gate. And was hoping that the Green Glue was going to be as close to a miracle as I was going to get based on all the great testimonies here.

Hi Orlando,

Sorry, I understood that your one wall had exposed studs. If that is so, the wall modification I described will take up as much room as the clips.

What's above this room? I assume additional living space? If clips on the ceiling are too much, consider using wood furring strips installed every 24" perpendicular to the joists. Not as good as clips, but better than installing drywall straight to the joists.

Hey Ted,

Thanks. If I put furring strips strips on the side wall as well, should I put them every 24"? I can do whatever I want as it is a totally flat wall. Also how far from the ceiling and floor should the frist strip be?

Thanks again.

I'm still confused, and I'm sure sorry.

If you have drywall on the walls, you would definately not want to put furring strip on the existing drywall. You would create a triple leaf. See here: http://www.greengluecompany.com/understandingTripleLeaf.php

If you have exposed studs, you should do the modified staggered wall suggested earlier. The staggered mod and the furring take up about as much space.

To answer your question, however, you place the furring every 24" along the wall or ceiling. First strip up 3-4".. and end with a strip 3-4" from ceiling

Thanks,

Hey Ted - Thanks for the info and sorry for not being clear about my situation.

Hopefully this will help.

The wall in question is what used to be my exterior wall. The house is in the northeast and about 60 years old if that helps any. It had a non load bearing brick wall face. When the brick was removed what was exposed was a 1/2" fiber felt kind of material which was nailed to wall length wood planks which were in turn attached to the main studs of the outer wall. With strong advice from both my architect and contractor I was convinced it was in my best interest to leave that alone. I was told I could just sheetrock right against that material, but I have concerns about sound transmission. Which is why I'm here. I really can't add too many inches as the room is already going to be narrower then desired. But doing at least double sheetrock is a necessity.


Thanks,
Orlando

I see, thanks for that clarification. Ideally, you'd build a double wall 1" or so away from that wall. But you have space constraints. If you are thinking about using Green Glue, I might suggest simply attaching the drywall right on that wall, and use two sheets.

You really can't GG to that 1/2" felt material, so add two sheets of drywall to get a reasonable constrained layer system there.

Thanks Ted.

I did find out some bad news that will actually be good news. It looks like I will have to add a second layer of floor in the bedrooms upstairs. This is so that the new floor will be even with the old floor. From reading this whole thread it seem to be a common thought a while ago. That Green Glue between floor layers is just about ideal.

Hi Orlando,

Are you adding 3/4" material? If so, consider two thin layers of 3/8" or 1/2" with two Green Glue layers at 50% coverage. Same amount of Green overall, but the multiple layers of Green are better.

Check out this page:

http://www.thegreengluecompany.com/usingGreenGlue.php

Near the bottom, it talks about different ceiling construction methods. I think, in general, mechanical decoupling (RSIC clips) is going to be better than GreenGlue. But if you can't afford using clips on the ceiling, you go to next best, which is a GreenGlue sandwich.


I agree with the above to use the Green Glue. If you can't afford the clips, the other approach is what I did (with the advice from the ever helpful Ted White). I did not want to go nuts with the clips, so I ran furring strips across all the I beams in the ceiling and then attached the 5/8" sheetrock to the ceiling and walls, followed by Green Glue and 1/2" sheetrock. Sealing all openings is very necessary with any approach for a soundproof room. I have ductwork going through the walls into the furnace room, but I cannot hear the noise through the flexduct. Using sealed doors (expensive is not really necessary) - I used a weather stripped metal external door for the main entrance ($250) and another one for the furnace door ($150). For the door to the equipment rack, I used a hollow wood door and filled it with "Good Stuff", used weather stripping and a door sweep (testing this week on this door). Creating light boxes (used GG in this project as well - see my thread) to seal in any ceiling holes was definately worth it. I cannot hear any high frequencies even at high volumes in the floor above the theater. At the bedroom level, most of the low frequencies are gone. I did crank the buttkickers to max for laughs and when I went upstairs the island was vibrating (which I thought was cool - wife didn't) - no need to crank them that high.

Green Glue is an excellent product and the service behind the company and knowledable persons (Brian, Ted, etc) is unbeatable.

thanks Green Glue,

Gary

Question: I have a basement room being finished which buts up against another finished room. The other 3 walls consist of one wall that will be against an outside wall, another one that will be about 2 feet off of another outside wall and then the 3rd wall which will be the wall to my mechanical room (furnace, hot H2O, electrical & storage). The ceiling has to be a drop ceiling...drywall is not an option. In a room configured like this, does mulitple layers of drywall and GG do much to it? Won't most of the sound transfer be through the ceiling? Should I consider decoupling the walls using RISC clips from the floor joists above? I mean, how much would I gain from doing those two things...GG and two layers of drywall and then the RISC clips to the floor joists knowing I'll have a drop ceiling?

Thanks.
Kevin

Hi Kevin,

Since the ceiling is a dropped ceiling with no drywall (Ceiling tiles only), I would just use signle layer drywall and call it a day. There will be so much sound going through the ceiling that the walls won't matter much.

Ted...for some clarification, I should have put more detail in my original post.

Well, it won't be ceiling tiles only...I plan on using ceiling tiles, a layer of sound dampener (a rubber gasket with insulation on both sides) on top of the tiles, then insulation between the floor joists themselves and about a 2-3" gap between the sound dampener and the floor joists. So...it's not "just a drop ceiling".

Thanks for your help.
Kevin

Well, If you want to shoot me a link to the vinyl/ insulation material, I'd be happy to take a look, but I'm feeing my answer will be the same.

Long time lurker first time poster....... I just wanted to add my two cents since I used the stuff in something other than a dedicaded theater room. I added an extra layer of sub floor as Orlando mentioned he may need/like to do. Thanks to the out of control housing market in California I moved into an apartment building I own that was built in the 1950’s. I chose an upstairs unit and usually work at night so I knew I had to do something about the floor or I could forget about using my home theater gear at night………. I thought about headphones (would mess up the hair), selling all my gear for the Spartan lifestyle (Gen X’er so not going to happen), and looked into some engineered board products that were either so expensive I could not stomach it or there was no info available regarding their performance or lack there of in the real world.

I ended up ordering Green Glue (tubes) and suckered some friends and family into the doing the floor install with me to save some money. I used ¾ plywood over the old existing hardwood (pretty thick stuff) sub floor and applied approximately 2-3 tubes of Green Glue per sheet covering every room except the bathroom which I did not demo completely. I have lived in the place for months now and I can tell you that it was very effective. I have steadily increased the playing level of my theater looking to find the level that my neighbors will complain. I finally asked them if they are ever bothered/woken by the loud theater/music or walking around late at night, etc. They told me the only way they know I am home is if there is water running! Since I can’t do much about pipes running through an old building I am pretty happy about the way things turned out. My only regret is not having enough time to do the adjoining walls when I did the floor. I just can’t get myself to take on a project like that while all my furniture is in.

I did had to cut the bottom off of doors for clearance, and trash two screw drivers and an extension cord that got “glued” while laying the floor. Small price to pay so I can continue to enjoy all my HT gear. The folks over at The Green Glue Company (they were Audio Alloy at the time) answered all of my phone calls and got the glue shipped out quickly since I was on a tight schedule to get it all done. Top notch group of people to deal with. Sorry about the long post, I figured I should be detailed and provide some decent info or not bother to post at all.

hey robo,

i'm glad your isolation plan worked out. :)

If i can take your post and sidetrack it just a little, i'd just take this chance to re-iterate that the floor is the best place to control footstep noise by a wide margin. I post that from time to time, but you can never re-iterate enough that if you want to control noise made by things hitting a floor, the floor level is where treatment will serve you best. If you deal with it at the ceiling level, its already in the structure and more likely to find a way to bite you.

ok, sorry about that sidetrack & i'm glad it worked out,

Brian

I could use a little advice. I am debating getting GG to help reduce sound transmission (mainly low frequency) from the HT in the basement through my house frame to the first floor. The HT room is 13'x23' and is connected to an adjoining room (in an 'L' shape) that is about 12'x15'.

Here are my questions. I want to add another layer of sheetrock with GG to the walls and ceiling. Since I have recessed lighting, what should I use to treat those? Do I need to do the same with electrical work boxes?

Finally, I don't want to wall off the adjoining room. There is a 12' opening to the room seperated by the main beam. Will my soundproofing efforts be in vain if I don't treat this room as well? As an alternative approach, I was thinking about installing some acoustical panels on sliding rails to contain most of the sound. Does anyone have any thoughts about this?

hey Min,

if you treat 1/2 of the lower room (partitioned by the beam) with GG, but not the other half, and the open side of the room has a stairway or something that leads to a door... ?

Could you post a sketch or drawing of the room?

Acoustical panels on sliding rails sounds like quite an ambitious project!

Brian

I have two tubes of Green Glue left over from working on my room, which has been a great success, what else can I do with Green Glue?

I have two tubes of Green Glue left over from working on my room, which has been a great success, what else can I do with Green Glue?

hey london, i'm very happy to hear your room turned out. :)

-loudspeaker cabinet
-equipment rack
-stage or riser
-add fiberboard and GG to the door
-one guy had a hard-surfaced coffee table and GG'd the bottom side

any of those seem reaosnable?

All sound like good ideas to me. Could it be used to reduce noise in a car?

All sound like good ideas to me. Could it be used to reduce noise in a car?

It could, and the results could be extremely favorable. But you have to constrain it, so the challenge would become putting GG onto a surface and then covering it with something, and cars don't generally have flat surfaces, so you might have trouble with the covering.

A paint-on damping material should be available from GG Co in about 45 days, and would lend itself much better to car applications.

Cars are interesting things as temperature is so extremely not-constant.

I am planning a family room by day/TV viewing room by night as part of finishing basement. I am also leaving about 15x17 unfinished to do a proper HT in 5 yrs or so. After much reading here I am wondering what approach I should take. Room is an "L" - very crude drawing is attached. I am planning to do 61" RPTV ($2500)/receiver($1000)/DVD player($400)/5.1 speakers ($1000).

I do not plan to do anything special regarding acoustics in this area. I'd like to have best sound with basic approach, and more importantly minimize sound to first floor or second (child's bedroom). This room will remain "as is" even after HT is added.

Room will be single layer drywall/frame/r19/block on three sides and a completely above ground wall with no block. Drywall ceiling, single layer to joists with r19.

Given that, am I wasting my money on receiver and speakers? I know $2000 isn't a lot by any means, but will my sound be so bad that I should just spend $500 for HTIB? Bottom line: Are all the tips and advice here to go from good/great sound to over the top awesome sound? I've had traditional stereo speakers forever and thought sound was great without a single thought to acoustics other than separate the speakers and point them toward listening area. Does 5.1 make things a lot more critical?

Also, given that this will be far from a "sealed" room, I'm guessing I shouldn't spend any cash on things like double layering drywall or clips or whatever? Any disagreements?

Hope these questions make sense and maybe will help others as well. Thanks in advance for feedback.

Hi Droht,

You might find some help on the AVS speakers forum.

Is a discount on green glue still available for non-paying members?

Hi Arch,

Yes certainly. You have a PM.

hey Min,

if you treat 1/2 of the lower room (partitioned by the beam) with GG, but not the other half, and the open side of the room has a stairway or something that leads to a door... ?

Could you post a sketch or drawing of the room?

Acoustical panels on sliding rails sounds like quite an ambitious project!

Brian

Brian - See if this sketch helps explain my situation.

nice sketch. I'll risk going too technobabbly here, but try to explain as best i can.

First, noise up the stairway. Is there a door of any kind at the top of those stairs, or at the bottom of those stairs where you have the dashed line, or would an open path exist from theater to the upstairs?

If this open path exists, and if it has carpet and perhaps soem other absorption placed on the walls, treating the theater might help. It might help because low-freqs around resonance points might come through the ceiling/walls more than through this winding stairway path.

It is also very possible that this open path, even though it is long and winding, will undo any isolation efforts you may undertake. It has alot of potential for flanking onise problems.


If you leave open the area where the large dashed line is, the effect of treating just the theater area will be compromised, i suspect. If you treated the entire lower area + had a door, you would be in good shape...

But... all of the downstairs that is open and exposed to loud sounds from the theater leads to potential flanking problems. Treat just the theater area, sound could certainly escape somewhere, and find a path.


In general, it is best to try to isolate a theater by building the theater as its own little box, and then address the sides of that box as best you can with your time/space/budget, etc.

Your situation is more complex than a box, and its tough for me to say exactly what the results would be, and i can't say "yes, use green glue" as i'm not really sure you'd get what you desired from doing so.

If that wasn't clear, please ask & i'll try to make it less jabbery. :)

Thanks Brian. I understood your reply. I will be adding a solid core door to the stairwell and already have a door at the top, so I should be in good shape there. I was wondering if there was a way to just treat the HT room with GG and use some sort of acoustic curtain system (if such a thing exists) so that I can reduce most of the sound energy from leaking into the adjacent room - necessitating the treatment of that room as well. Also, how do you treat the recessed lighting and other electrical boxes. I am at Cedia this week so hopefully I'll get some ideas.

hey min,


solutions for lights range from building little boxes behind the lights to just leaving the cans.
a very well sealed can, as small as possible, won't have a hugely negative effect on performance. But the impact of cans might vary from type to type, and the seal is of paramount importance.

Building a box behind the lights is a sure-fire way to handle the situation, there are a variety of threads on the topic of lights and how they ar edealt with, but i don't have a link to one off the top of my head.


An acoustic curtain will never be a serious noise barrier. It can't be sealed, the weight is minimal, no air cavity, and so forth. But maybe 10dB of isolation (vs no curtain) could be had, which would be better than nothing, but not great in the grand scheme.

Hello Everyone,

I recently bought a house (from '74) and I decided to take up the basement. Well, at 4am I am waking up with the noise coming from upstairs when others get up to go to work. Upstairs there is carpet with a squeaky wood floor beneath.. Since I hear all types of noise like alarm clocks, speech, footsteps, etc. I am in dire need of a solution. I have been reading a lot about resilient channels, insulation, soundboard, green glue, etc, etc..

At this point I have resilient channels, insulation, GP hushboard, acoustic caulk and 1/2" drywall.... im going crazy trying to decide what to do, what to use, what not to use, if should i get GG or not, if should i use rc's or not ... so anyway, my questions are...

Will sandwiching the hushboard and the drywall with GG be sufficient? Or is it at least pretty comparable to two 1/2" sheets of drywall with GG in between?

There is talk about how using resilient channels are so prone to "short-circuits" - so how does a short-circuit using resilient channels differ from screwing two GG sandwiched sheets of drywall directly to the joists? Is it not the same principle where the energy passed onto the joists is passed through the screws and onto the drywall making it vibrate?

Along those same lines, is it better to screw one sheet onto the ceiling first, apply the GG, and then screw-in the other one? Or, make the GG sandwich at floor level and screw them both in? Any difference in this ?

I'd like to add that I will be putting R-19 batts in between the joists. Will I have better performance using the RC's or should I just return them and use GG?
What would be better, a bead of acoustic caulk or GG on each joist? Or, is this even necessary/helpful?

Also, I am wondering how worried I should be about the perimeter of the rooms. Since there are 2x4 stud walls up against the cement walls there will obviously be a cavity there from the inside edge of the 2x4 wall to the outer walls of the house (looking at it at the joist level). Is there going to be a lot of noise travelling down the outside 2x4 walls? I guess I should also add that I put R-13 insulation in these walls.

My biggest thing right now is I've spent quite a bit already on the material mentioned above and do not really wanna spend more but at the same time I don't want to sacrifice it and later say I should of just done this or that...

Sorry about all the questions, any help is appreciated.

-Israel

Hello Everyone,

I recently bought a house (from '74) and I decided to take up the basement. Well, at 4am I am waking up with the noise coming from upstairs when others get up to go to work. Upstairs there is carpet with a squeaky wood floor beneath.. Since I hear all types of noise like alarm clocks, speech, footsteps, etc. I am in dire need of a solution. I have been reading a lot about resilient channels, insulation, soundboard, green glue, etc, etc..

At this point I have resilient channels, insulation, GP hushboard, acoustic caulk and 1/2" drywall.... im going crazy trying to decide what to do, what to use, what not to use, if should i get GG or not, if should i use rc's or not ... so anyway, my questions are...

israel, Hi, welcome to the forum. I can appreciate how complicated and confusing something like this can be when you start thinking about it.


what is hushboard? is that a wood fiber typ eof soundboard?

Will sandwiching the hushboard and the drywall with GG be sufficient? Or is it at least pretty comparable to two 1/2" sheets of drywall with GG in between?

There is talk about how using resilient channels are so prone to "short-circuits" - so how does a short-circuit using resilient channels differ from screwing two GG sandwiched sheets of drywall directly to the joists? Is it not the same principle where the energy passed onto the joists is passed through the screws and onto the drywall making it vibrate?

Well, resilient channel works as a decoupling mechanism. Its flexibility helps to (at some frequencies) keep vibration/sound from moving from the drywall inside one room to the studs/drywall on the other side. Decoupling keeps energy (at some frequencies) from moving from one place to another.

Green Glue is damping. That's a different principle, damping materials work by dissipating vibrational energy. So instead of stopping it from moving from point A to point B it works to dissipate much or most or all of it as it moves from point A to point B.

That's a simplified comparison, but a fair one. I can blabber on about it if you're interested.

Along those same lines, is it better to screw one sheet onto the ceiling first, apply the GG, and then screw-in the other one? Or, make the GG sandwich at floor level and screw them both in? Any difference in this ?

I'd like to add that I will be putting R-19 batts in between the joists. Will I have better performance using the RC's or should I just return them and use GG?
What would be better, a bead of acoustic caulk or GG on each joist? Or, is this even necessary/helpful?

you should use insulation with either option. Basically, insulation is almost always advisable.

We have gotten away from advising the use of GG on the joists, though you can do so if you wish. For the same $$$, you get more with it between the layers.

The question of what is better depends on what type of noise one is trying to isolate. For speech and normal sounds, many things are effecive, including properly installed RC. At middle and high freqs properly installed RC is a very good choice. At lower freqs, as relevant to theater and the like, RC has problems and limitations beyond short circuiting.


Also, I am wondering how worried I should be about the perimeter of the rooms. Since there are 2x4 stud walls up against the cement walls there will obviously be a cavity there from the inside edge of the 2x4 wall to the outer walls of the house (looking at it at the joist level). Is there going to be a lot of noise travelling down the outside 2x4 walls? I guess I should also add that I put R-13 insulation in these walls.

My biggest thing right now is I've spent quite a bit already on the material mentioned above and do not really wanna spend more but at the same time I don't want to sacrifice it and later say I should of just done this or that...

Sorry about all the questions, any help is appreciated.

-Israel

Noise can potentially get in or out of a room by almost any path. Its a frustrating reality.

In your case the footsteps will be the toughest to deal with. If you could post a simple sketch i could take a look at where the noise is coming from and construction and perhaps offer a bit more. I do confess, though, that i'm not always good at interpreting drawings.

I hope that was at least a start,

Brian

Hey folks,

as this is the GG thread, just a few comments on things that are going on.

i've offered alot of responses to alot of questions about silicone and acoustical sealants and liquid nails and other products and this's and thats. And i'm very happy to say that we have had the time to schedule tests in an independent lab to deliver some #'s to outline what has been said. That should be alot of fun.

Brian

Yes, the hushboard looks like it's made of wood fiber, it's somewhat flexible, light and is almost like a thick cardboard.

As far as the construction, when I tore up the main floor bathroom, the floor had vinyl, some kind of 1/4" sheet of board, then particle-board, then ply-wood. (The joists are approx 8" high.) So, I am not entirely sure but imagine that it would be the same type of construction in the living room and bedrooms except instead of vinyl, wood floor and on top of that carpet padding and carpet.

Since I haven't made a diagram I'll just explain as best as I can. In the basement, the two rooms are approx 9x11 and 10x10. All around the stud walls (16" on center) are up against the cement retaining walls and these at the same time are butted up against the joists above. Which is where I am concerned, in this area, do you think that I am still going to get a lot of sound coming through? If there isn't anything done there, other than the insulation above and in the walls is this something that is going to affect the performance of the sound dampening done on the ceiling?

Thanks!

Brian, my home came with a completed and enclosed 20'x20'x9' space for a home theater or gameroom. The walls have been textured, painted, etc. and carpet has been installed. I have a couple of questions about green glue.

1. My plan is to put up another layer of sheetrock with green glue over the existing walls and ceiling, as two of the walls fully or partially face bedrooms. Will there be any problem putting Green Glue over textured drywall? To be clear, it is what is known as "knock down" texture and does not protrude far from the walls.

2. I may have to cut access holes in the drywall to run the cables that the builder didn't run before adding the second layer of drywall, though I plan to patch anything that I cut. Will this be a problem?

3. The odd thing about my house is that the media room is directly over the garage, and is a good 6" shorter than the rest of the second story floors. When people walk on the floor, you can feel it, unlike the other areas on the second floor. I'm planning on putting another layer of plywood across the floor in the hopes of stiffening it up and reducing vibrations to give it a more solid feel, and I'm wondering if Green Glue will work well for that?

Thank you.

Brian, my home came with a completed and enclosed 20'x20'x9' space for a home theater or gameroom. The walls have been textured, painted, etc. and carpet has been installed. I have a couple of questions about green glue.

1. My plan is to put up another layer of sheetrock with green glue over the existing walls and ceiling, as two of the walls fully or partially face bedrooms. Will there be any problem putting Green Glue over textured drywall? To be clear, it is what is known as "knock down" texture and does not protrude far from the walls.

2. I may have to cut access holes in the drywall to run the cables that the builder didn't run before adding the second layer of drywall, though I plan to patch anything that I cut. Will this be a problem?

3. The odd thing about my house is that the media room is directly over the garage, and is a good 6" shorter than the rest of the second story floors. When people walk on the floor, you can feel it, unlike the other areas on the second floor. I'm planning on putting another layer of plywood across the floor in the hopes of stiffening it up and reducing vibrations to give it a more solid feel, and I'm wondering if Green Glue will work well for that?

Thank you.

for 1. : the basic effect of the texture is to cause the glue to spread less when the other layer of board is screwed up. so it results in a somewhat thicker film with less overall coverage. you can compensate for that by using more glue, BUT you may not find htat necessary. It should work fine, just consider extra glue optional, don't consider it compulsory or even strongly recommended. 3 tubes/board with a knockdown texture typically yields results a bit better than 2 tubes/board with flat surfaces

for 2: just make sure the patches don't stick out to prevent the two boards from squeezing up to one another. its fine if its flat, its bad if it protrudes

for 3: should work great for that. If there is a room in particular wehre footsteps in that room cause disturbance in the theater, GG in that room might be beneficial.

Yes, the hushboard looks like it's made of wood fiber, it's somewhat flexible, light and is almost like a thick cardboard.

ok, got it. as a general rule, drywall is preferable to this type of product as its alot heavier. It would be better to return that material for drywall if that is an option.

As far as the construction, when I tore up the main floor bathroom, the floor had vinyl, some kind of 1/4" sheet of board, then particle-board, then ply-wood. (The joists are approx 8" high.) So, I am not entirely sure but imagine that it would be the same type of construction in the living room and bedrooms except instead of vinyl, wood floor and on top of that carpet padding and carpet.

well, that's a pretty substantial (heavy) floor, which is all things equal a good thing.

Since I haven't made a diagram I'll just explain as best as I can. In the basement, the two rooms are approx 9x11 and 10x10. All around the stud walls (16" on center) are up against the cement retaining walls and these at the same time are butted up against the joists above. Which is where I am concerned, in this area, do you think that I am still going to get a lot of sound coming through? If there isn't anything done there, other than the insulation above and in the walls is this something that is going to affect the performance of the sound dampening done on the ceiling?

Thanks!

In your situation, where you indicate different sounds coming from different places in the house, and not low-frequency-heavy theater noises.

I suspect that for the alarm clocks and maybe other light noises to be problematic, you might have a seal problem. Some type of open air path between the alarm clock and your room. Often this is just poorly sealed - or not sealed construction.

It may well prove that the best route for you in trying to control the sounds is to sort of tear up your wall (as you would have to to install the resilient channel or to put GG on the joists and/or studs), and then build a new shell inside your room.

I would recommend sound clips (RSIC clips from pac-intl.com or ISOMAX from kineticsnoise.com or one of these guy's distributors). These clips are in essence like resilient channel, but superior, and not prone to short circuiting.

While the joists and walls are open, put normal fiberglass insulation inside them (the cheap kind, as you might find at home depot or lowes), then clips with the hat channel, and 1 or 2 layers of drywall.

If you treat all the sides of your room, this does involve some work and some expense, but it allows you to be sure some things are accomplished. For example, your concern about the concrete joint can be dealt with, and you can ensure that the shell of your room is well sealed by, in essence, starting from scratch.

The squeaky floors above can be addressed really well with Green Glue, but you would have to take up one layer of board to put GG in between the two layers. Take up the particleboard, apply GG, screw it back down, the squeaks should be gone for all eternity. But this is another level of cost and work, and if it was my room i would start with the sound clips and the shell of the room as described above.

For low-freq containment, ala theater, i'd really recommend GG and double drywall on the clips, but for noises like alarm clocks, people talking, and so forth, the need for mass and damping will not be as great.


If that made less than enough sense, please let me know and i'll try to post a more concise version.

I would, if it was my situation, take out the ceiling and wall drywall in your room, add insulation, then add clips/hat channel and new drywall, taking care to make sure the room is sealed as i went.

Thank you Brian.

Thanks Brian for the info. I guess I will take that back since I can get about two sheets of drywall even if it's 1/2" for the price of one of those 4'x8' hushboards.

I was wondering if you or anyone has any experience with something I saw on a soundproofing website called "sound isolation padding tape?" They recommend it be doubled-up on every other stud or joist and to put the screws on the studs/joists that have the tape on them. It's supposed to be similar to the de-coupling technique of resilient channels but I was wondering if anyone knows how good it is? Would this be any good with two drywall panels that have GG in between?

-Israel

I bought a house and moved in about 1 1/2 months ago. I had the perfect theatre room (3 concrete backing on walls on 3 of the 4 walls). One of the walls backs out onto the stairs that are going upstairs. I drywalled it all and painted 3 of the 4 walls already. Roof is still not done.

Would it be possible to get advise on these things?:

1. The wall that is backing onto the stairway doesn't have insulation in between, but more importantly it has a cold air return built into one of the studded gaps between the drywall. Would it be worth adding another layer of drywall with GG to the whole wall and still have this very apprent sound leak (the cold air return)

2. Is it benefitial to use sheetrock with GG between the joists on the floorboard for upstairs using green glue? How much isolation will this provide? (STC). I would then stuff 12" fuffy fiberglass insulation between the joists and cover with fabric. I then plan later down the road (unless the sound from the theatre CAN'T be igored) to do the whole ceiling with 2 layers of 1/2" and green glue.

-Robb.

Hi, I am finishing my basement and need some advice on which walls in the home theater would require the GG. Like the last poster, I have a room which is basically 3 sides drywall with poured cement wall behind it -- so I am not concerned with noises or sound isolation for those 3 walls. I am concerned with the back wall and the ceiling.

I was planning on just putting GG sandwhich on the backwall and ceiling, and just regular drywall on the 3 concrete walls. But because those 2 GG surfaces would now have dampening, and the other 3 would reflect sound, would this room have odd acoustical properties (i.e. sound strange)? If so, am I better off doing a full GG spread on the 2 surfaces which I need sound isolation, and 50% GG on the other 3 cement walls?

Any advice or thoughts are appreciated. Thanks!

Anyone have a few tubes they could sell me so I can test it out before buying a whole case?

You are concerned with all the walls. You can have flanking paths otherwise. Rather a do it right, or not at all scenario.

Minicus - how do you propose testing it?

You are concerned with all the walls. You can have flanking paths otherwise. Rather a do it right, or not at all scenario.

Minicus - how do you propose testing it?

So you are saying that it is not even worth GG on the ceiling?

-Hutz

Thanks Brian for the info. I guess I will take that back since I can get about two sheets of drywall even if it's 1/2" for the price of one of those 4'x8' hushboards.

I was wondering if you or anyone has any experience with something I saw on a soundproofing website called "sound isolation padding tape?" They recommend it be doubled-up on every other stud or joist and to put the screws on the studs/joists that have the tape on them. It's supposed to be similar to the de-coupling technique of resilient channels but I was wondering if anyone knows how good it is? Would this be any good with two drywall panels that have GG in between?

-Israel

hey Israel,

tapes like that can help a bit at middle and high freqs, but ultimately can't deliver true decoupling because the screws are still through the drywall into the studs every 12 or 16 inches. It would be like 100% short-circuited resilient channel, perhaps.

we do find that tapes like that are a good add-on to a GG single wood stud wall, but aren't necessary on a clip wall (just a waste, as the clip wall is already really well decoupled). Also unnecessary for hte same reason on a double stud wall (already decoupled).

I have some test data for a product like that somewhere or other, the results were a little boost at higher freq's, with no real effect at lower freqs.

It isn't a bad product or a bad idea at all, but it cannot deliver significant improvements, only modest improvements at middle/high freqs. Its low in cost, however, so it might be just what some persons desire.

Brian

Hi, I am finishing my basement and need some advice on which walls in the home theater would require the GG. Like the last poster, I have a room which is basically 3 sides drywall with poured cement wall behind it -- so I am not concerned with noises or sound isolation for those 3 walls. I am concerned with the back wall and the ceiling.

I was planning on just putting GG sandwhich on the backwall and ceiling, and just regular drywall on the 3 concrete walls. But because those 2 GG surfaces would now have dampening, and the other 3 would reflect sound, would this room have odd acoustical properties (i.e. sound strange)? If so, am I better off doing a full GG spread on the 2 surfaces which I need sound isolation, and 50% GG on the other 3 cement walls?

Any advice or thoughts are appreciated. Thanks!


Hey Lurker,

using GG in 2 of the walls and not in the other won't stop sound from bouncing off of the walls. I started a thread a few months ago about the apparent sound absorption properties of walls, and damping materials do seem to have some effect, but not at higher freq's and not to the degree that you're thinking. Good thought, but in this case you don't have to worry about it.

for the 3 walls by concrete, did you plan to frame away from the concrete and add drywall?

Brian

I bought a house and moved in about 1 1/2 months ago. I had the perfect theatre room (3 concrete backing on walls on 3 of the 4 walls). One of the walls backs out onto the stairs that are going upstairs. I drywalled it all and painted 3 of the 4 walls already. Roof is still not done.

Would it be possible to get advise on these things?:

1. The wall that is backing onto the stairway doesn't have insulation in between, but more importantly it has a cold air return built into one of the studded gaps between the drywall. Would it be worth adding another layer of drywall with GG to the whole wall and still have this very apprent sound leak (the cold air return)

Its possible that the sound leak could make adding GG and drywall a waste of money, but i can't answer w/o being there. An extreme example is an open door. Have room w/music system, noise is disturbing the rest of the house, so you upgrade the walls to GG double stud... but don't add a door (which was missing). You won't achieve much.

Ductwork can be (and is) a part of a very good isolation scheme, though. Generally when ductwork connecting two rooms is longer, has bends, has insulation lining the duct, the ductwork has higher levels of sound isolation.

Ductwork doesn't have to prevent good isolation, but it can at times. You will have to use a good level of prudence to assess how much noise is coming through the duct and if measures such as the above (duct liner, bends in the ductwork, etc.) can be implemented.

2. Is it benefitial to use sheetrock with GG between the joists on the floorboard for upstairs using green glue? How much isolation will this provide? (STC). I would then stuff 12" fuffy fiberglass insulation between the joists and cover with fabric. I then plan later down the road (unless the sound from the theatre CAN'T be igored) to do the whole ceiling with 2 layers of 1/2" and green glue.

-Robb.

Robb,

its a good idea, and an idea that AVS folks came up with. As for how many STC points are gained, the answer to that will vary with what type of ceiling is below it and other variables. I tend to look at impact noise (noise from the floor above) reductions as the biggest benefit for this type of work.

When applying drywall between the joists, make sure to seal it in below the sub-floor to ensure that there aren't direct air paths from theater to the room above (often floors aren't well sealed). Just a bead of caulk between the joist and the drywall will do the trick.

On a side note, STC isn't a very good measure of isolation for theater purposes. The reason is that the STC rating only considers frequencies down to 125hz, where theater noise has enormous sound energy below that frequency.

On another side note, its my hope to fairly soon test for absorption and isolation constructions like you tentatively describe: one side of joist or stud cavities open, and a large mass of GG/drywall on the other side. I think the outcome would be very interesting.

Brian

We have finally had a chance to test some conventional adhesive. By that i mean commonplace fairly rigid adhesives (liquid nails, drywall adhesive, etc.). In this case the material was OSi Drywall adhesive.

Long ago, one of my first posts on AVS was related to a debate about the use of rigid adhesives in walls and what the effect of that would be. The theoretical problem with using a rigid adhesive is that it stiffens the panel which lowers the coincidence dip and raises the frequency of the low-frequency resonance.



When the rigid adhesive was on just one side of the wall, the performance was about the same as if no adhesive was utilized. Some changes are evident, but the net final result is quite similar to if no rigid adhesive was utilized.

However, when the rigid adhesive is used on both sides, the results are disastrous and performance is very poor.

I'll enter some calculated performances in a minute or two to highlight the gains and losses of these different assemblies.


I also include in that graph a comparison of conventional drywall with no adhesive, conventional rigid adhesive, 3 re-tests of GG on that assembly, and one of 2 tests we've run on a competitive damping product. The competitive product falls well short of matching GG's performance, the entire test was independently contracted and filmed to ensure good prudence.

This last set of data highlights why i caution people on putting things like acoustic sealant and the like between layers of their walls. You risk - even if some damping performance is delivered - very minimal benefits while incurring some cost. In this case, its best to stick with tested stuff like stagg studs or ISOMAX or RSIC when not wanting to use GG.

Brian

Hey Lurker,

using GG in 2 of the walls and not in the other won't stop sound from bouncing off of the walls. I started a thread a few months ago about the apparent sound absorption properties of walls, and damping materials do seem to have some effect, but not at higher freq's and not to the degree that you're thinking. Good thought, but in this case you don't have to worry about it.

for the 3 walls by concrete, did you plan to frame away from the concrete and add drywall?

Brian


Cool -- so then I should be able to get away with just doing the ceiling and back wall. Yes, I would be framing away from the concrete and adding drywall.
I am not too concerned with flanking noise, as there will be leaks anyway from the entrance door and closet door. I am not expecting a perfectly quiet room, but did want to improve on the 2 biggest areas that I thought I could improve.

We have finally had a chance to test some conventional adhesive. By that i mean commonplace fairly rigid adhesives (liquid nails, drywall adhesive, etc.). In this case the material was OSi Drywall adhesive.
...
When the rigid adhesive was on just one side of the wall, the performance was about the same as if no adhesive was utilized. Some changes are evident, but the net final result is quite similar to if no rigid adhesive was utilized.

However, when the rigid adhesive is used on both sides, the results are disastrous and performance is very poor.

I'll enter some calculated performances in a minute or two to highlight the gains and losses of these different assemblies.

I also include in that graph a comparison of conventional drywall with no adhesive, conventional rigid adhesive, 3 re-tests of GG on that assembly, and one of 2 tests we've run on a competitive damping product. The competitive product falls well short of matching GG's performance, the entire test was independently contracted and filmed to ensure good prudence.

This last set of data highlights why i caution people on putting things like acoustic sealant and the like between layers of their walls. You risk - even if some damping performance is delivered - very minimal benefits while incurring some cost. In this case, its best to stick with tested stuff like stagg studs or ISOMAX or RSIC when not wanting to use GG.

Brian,
Thanks for the update on your testing. I appreciate the honest and data-backed approach that the Green Glue Company (and yourself) takes in promoting your product.

I was at CEDIA a couple weeks ago and saw a number of "sound proofing" companies promoting various products. Some of them appeared to have done some independent testing, but many of them had no independent data but still were making pretty outragous claims.

It is too bad that all companies do not provide the same type of quality information and testing results that you do. (Actually, on second thought, if they were as honest as the GG company, they probably would not be in business :eek: )

On a side note, I saw Ted White at CEDIA. It was great to finally meet him after chatting with him online and over the phone. He is a great guy!

- Scott

Green Glue seems to be thee best out there, We'll at least from what I have read. I need to order a ton of it to do my 13x30x8' theater. I made the mistake of liquid nails on the doubl layers. So I will be adding a third layer of 5/8 with green in between. That's allot of drywall :)

Green Glue seems to be thee best out there, We'll at least from what I have read. I need to order a ton of it to do my 13x30x8' theater. I made the mistake of liquid nails on the doubl layers. So I will be adding a third layer of 5/8 with green in between. That's allot of drywall :)

That is alot! but lots of drywall is a good thing. :)

Brian,
Thanks for the update on your testing. I appreciate the honest and data-backed approach that the Green Glue Company (and yourself) takes in promoting your product.

I was at CEDIA a couple weeks ago and saw a number of "sound proofing" companies promoting various products. Some of them appeared to have done some independent testing, but many of them had no independent data but still were making pretty outragous claims.

It is too bad that all companies do not provide the same type of quality information and testing results that you do. (Actually, on second thought, if they were as honest as the GG company, they probably would not be in business :eek: )

On a side note, I saw Ted White at CEDIA. It was great to finally meet him after chatting with him online and over the phone. He is a great guy!

- Scott

Teds a great guy :cool:

I'm very glad that you like all the data. Its hoard's of work & nickels and all of that & i hope time smiles favorably on all the effort. :)

Cool -- so then I should be able to get away with just doing the ceiling and back wall. Yes, I would be framing away from the concrete and adding drywall.
I am not too concerned with flanking noise, as there will be leaks anyway from the entrance door and closet door. I am not expecting a perfectly quiet room, but did want to improve on the 2 biggest areas that I thought I could improve.

Well, using GG on only one side won't cause room acoustics problems.

And you don't need to use GG on all sides to get good isolation, but to DE's point, you will have to have a good plan that includes all sides.

Your plan sounds pretty good, you can if need be upgrade the side walls later... But do be careful about the door and closet door, even if they can't be as good as the rest, it'll be well worth the effort to make them as good as they can be.

good luck & post with questions if you have 'em

I hear alot of "two walls are concrete and I don't need (want) framing, GG, Clips, etc on those two walls".

We can debate until the cows come home about the sound isolation needs for those walls (which would need to take into account, home construction methods, depth of concrete under ground level, etc, etc); however, you do need to treat those walls. Your wall impedances are considerably different and those concrete walls are going to make tuning your bass response much more difficult. Don't be tempted into using 1" firring strips and foam insulation and thinking you've done a good thing. The likelihood is you've made your bass response problems bigger, not smaller, problems.

I hear alot of "two walls are concrete and I don't need (want) framing, GG, Clips, etc on those two walls".

We can debate until the cows come home about the sound isolation needs for those walls (which would need to take into account, home construction methods, depth of concrete under ground level, etc, etc); however, you do need to treat those walls. Your wall impedances are considerably different and those concrete walls are going to make tuning your bass response much more difficult. Don't be tempted into using 1" firring strips and foam insulation and thinking you've done a good thing. The likelihood is you've made your bass response problems bigger, not smaller, problems.

Hi Dennis, I think I am understanding your point now.
So you would recommend doing the same treatment on all walls (in my case GG sandwhich) so that the freq response would be the same from all surfaces (except the floor)? Is that correct?

Ok, I'm in the beginning stages of my home theater (new construction home , HT in the basement, and basement framing has started). I want this room to be as sound proof as possible so I want to make sure I'm using the best techniques possible.

The room is 26 by 15, we have 9' ceilings.

My plan right now is to double stud the two interior walls and single stud the cement walls. All walls and ceiling will have double drywall with GG. The ceiling will be framed seperately with 2x8's that I plan on only have touch the framed room within a room in the HT so no other wood that touches the rest of the house. I'm going with extra bends in the HVAC with insulated vents and air returns. I'm using and extrior door for the only entry into the room. All the insulation will be standard cheap fiberglass insulation.

I want to be able to play this faily loud and not have it travel in the house, since the HT will be under a bedroom and don't want to wake someone at night with loud sounds.

Is there anything I need to consider that I'm not right now. I think I'm spending enough already to get his sound proof so I'm mainly worried about the best practices, yet if there is a products I should consider that won't add much in cost I will.

Thanks for your help
Patrick

My room is above the garage and two sides adjoin to bedrooms. I did 2x5/8 drywall with 100% GG coverage on all 4 walls and ceiling, with regular fiber insulation in the walls and blown on the ceiling, and put an exterior door in with weatherstripping all around (including a threshold to seal the bottom). Here are the things I've learned from my experience that may help you:


Get the door jamb installed before the drywall goes up (I was delayed and had to end up cutting back the drywall to get it in and that left me with the difficult challenge to fill the gap -- which I did quite well with joint compound but there were side effects that caused other problems -- you can read about it in my thread if you are interested).
Your biggest source of sound leak will be air gaps. I didn't know how to treat the outlet boxes for example and I can talk through those just fine. I've seen people wrap them with some material and spread acoustical caulk all over it as well, don't know the results but I would investigate that -- more than likely this WILL BE your biggest sound leak in your room if you do everything else correctly.
Be sure and use a threshold on the bottom of the door -- makes a big difference.
When you take the door off for painting it be sure and mark which hinges go in which spot (use a sharpie for example on the backside of the hinge and on the wood prior to taping it off so it's there when you remove the tape). They look the same but are not quite and rehanging the door will be a nightmare if you don't know which is which.
Since the upstairs is your immediate concern I would be sure and build boxes that are GG'd for any recessed lights (or anything else that goes through the ceiling to be honest). It's amazing how much sound goes through a little hole. Or rather how much sound is blocked by the GG'd drywall and lets you pinpoint the sound through the leak more easily (hard to say -- the reason I say this was my brother was on the other side of a wall in a garage attic space and the only way I could communicate with him was to shout through one of my power outlet boxes, there was little to no sound anywhere else).


Okay, having pointed out all the things to be aware of and avoid I would also like to add the following:

I LOVE MY GREEN GLUE INSTALL!!

That's right, even with the minor problems I still have, I cannot believe how great it works. Especially if you consider that you go to all this cost and effort and can't really test it until the room is half way done (or about 75% in my case). I was quite nervous that all this effort (and money) was being put into my dream theater and the big question always loomed: Would I be able to watch movies and TV and sound levels I like without having my wife come pounding on the door late at night yelling at me to turn it down?!

The answer (which I learned only a couple of weeks ago) is YES. I can watch movies at my preferred sound levels (which is nervous loud -- I still worry she'll come banging on the door which is what always happened in the past) yet every morning I ask her if she heard anything the night before and she didn't. Nor do the kids wake up on the rooms beside the theater.

Sunday evening I had my family over for a quick sound/picture demo and in the middle of oohing and aahing over the Master and Commander battle scene and the Incredibles island fight scenes (with the kids) my brother came in (who's had plenty of viewing time before so knows how it sounds inside) made my favorite comment of the night: "Dude, I couldn't even hear it at the top of the stairs and could barely hear it outside the door!" SWEET!

So yeah, spend a little more time and effort to close up those last holes/leaks and you'll be happy as can be!

Mike

I thought I’d post a question for Brain (or anyone else) in this thread. I’m planning on doing the “typical” install for my rom with double walls, suspended ceiling from RSIC/Isomax, double drywall with GG on walls an dceiling, and double airlock-type door. I’m debating whether with this construction method I need/want to do anythign with the floor (concrete slab in a basement).

I read the February, 2006 thread with the debate between Brian R. and Terry M. on “floating floor” systems and I think it would be safe to summarize that Brian is not a big fan of RIM or other floating floors for this application. Products like acoustikmat have been recommended, but there have been few posts regarding its usefulness and it is quite expensive. Two layers of plywood separated by GG would also be a possibility, and it would actually be much cheaper than acoutikmat. Would this provide any benefit?

Essentially, would you choose:

a) concrete → vapor barrier → pad → carpet
b) concrete → vapor barrier → plywod → GG → plywood → pad →carpet
c) concrete → GG → plywood → pad →carpet

Hi Kevin,

The slab is a very significant mass, and is generally that last surface to turn your attention toward for sound isolation. Wall and ceiling isolation as well as flanking considerations are generally still the weak link(s) even after basic room isolation treatment. I'd say you won't need to consider the floor, or at least at this point.

Generally the weak points are flanking pathways, when all is said and done. Ventilation, outlets and doors are prime candidates for scrutiny. http://www.greengluecompany.com/understandingFlankingNoise.php

Thanks, Ted. That's why I asked.

I'll have a separate HVAC system for this room , so ventilation shouldn't spread sound to the rest of the room, and outlets will be in columns rather than the wall so there won't be sound transmission there either. Two well sealed doors is about the best I can afford to do there. Even with all that, I know there is still sound transmission, particularly through the ceiling would be my guess. I just didn't know what magnitude that would be vs. the floor and whether treating the floor would be worthwhile.

Would there be any benefit to adding GG to a theater that has double doors as the entrance? The doors are solid oak, but I know that doors are one of the worst areas to keep sound in. I just don't want to go through the trouble if it would be beneficial.

mmattia,

Oak doors are a lot of mass, obviously. Seals would be your first priority. Seal them and perhaps try them before doing anything else.

I hear alot of "two walls are concrete and I don't need (want) framing, GG, Clips, etc on those two walls".

We can debate until the cows come home about the sound isolation needs for those walls (which would need to take into account, home construction methods, depth of concrete under ground level, etc, etc); however, you do need to treat those walls. Your wall impedances are considerably different and those concrete walls are going to make tuning your bass response much more difficult. Don't be tempted into using 1" firring strips and foam insulation and thinking you've done a good thing. The likelihood is you've made your bass response problems bigger, not smaller, problems.

There is no question, folks, that concrete could cause you problems, and DE's approach is indeed very prudent.

But, i am always hesitatnt to recommend "too much", so i tend to make conservative recomendations, perhaps. And in some situations, you may (from an isolation standpoint) not have issues with exposed concrete walls.

If your goal is to make sure things work out the first time, follow DE's advice. :)

Ok, I'm in the beginning stages of my home theater (new construction home , HT in the basement, and basement framing has started). I want this room to be as sound proof as possible so I want to make sure I'm using the best techniques possible.

The room is 26 by 15, we have 9' ceilings.

My plan right now is to double stud the two interior walls and single stud the cement walls. All walls and ceiling will have double drywall with GG. The ceiling will be framed seperately with 2x8's that I plan on only have touch the framed room within a room in the HT so no other wood that touches the rest of the house. I'm going with extra bends in the HVAC with insulated vents and air returns. I'm using and extrior door for the only entry into the room. All the insulation will be standard cheap fiberglass insulation.

That is a completely ideal arrangement. Seperate ceiling joists for a true room within a room, double drywall all around, (i assume the single studs by the concrete won't be touching the concrete?).

To keep the door up to somewhere near the performance of the walls and ceiling, communicating doors (2 doors forming an "airlock") is the best bet. I know that isn't always practical or desirable, but it is the highest performance option for those times when it can be done.

I want to be able to play this faily loud and not have it travel in the house, since the HT will be under a bedroom and don't want to wake someone at night with loud sounds.

Is there anything I need to consider that I'm not right now. I think I'm spending enough already to get his sound proof so I'm mainly worried about the best practices, yet if there is a products I should consider that won't add much in cost I will.

Thanks for your help
Patrick

Patrick, you might consider adding a layer of rubber mat and sub-floor to the floor (this is a commonly recommended practice on this forum), and you will have to (as always) make 110% sure that the room is well sealed, but your plan is idyllic and should deliver the goods.

Also, Patrick, if you do use a single door on the theater, you might ifnd that improving the door to the bedroom above can help. Its remarkable how often bedroom doors are the weak link (especially if higher frequencies wind up in the bedroom).

finally, you could consider adding some amss/damping to the bedroom floor before putting up the ceiling joists and drywall. This will help a bit with sound transmission going up to be sure.

But, please don't think i'm recommending any of those as necessary, your design is as i mentioned really, really good.

good luck & post with questions

My room is above the garage and two sides adjoin to bedrooms. I did 2x5/8 drywall with 100% GG coverage on all 4 walls and ceiling, with regular fiber insulation in the walls and blown on the ceiling, and put an exterior door in with weatherstripping all around (including a threshold to seal the bottom). Here are the things I've learned from my experience that may help you:


Get the door jamb installed before the drywall goes up (I was delayed and had to end up cutting back the drywall to get it in and that left me with the difficult challenge to fill the gap -- which I did quite well with joint compound but there were side effects that caused other problems -- you can read about it in my thread if you are interested).
Your biggest source of sound leak will be air gaps. I didn't know how to treat the outlet boxes for example and I can talk through those just fine. I've seen people wrap them with some material and spread acoustical caulk all over it as well, don't know the results but I would investigate that -- more than likely this WILL BE your biggest sound leak in your room if you do everything else correctly.
Be sure and use a threshold on the bottom of the door -- makes a big difference.
When you take the door off for painting it be sure and mark which hinges go in which spot (use a sharpie for example on the backside of the hinge and on the wood prior to taping it off so it's there when you remove the tape). They look the same but are not quite and rehanging the door will be a nightmare if you don't know which is which.
Since the upstairs is your immediate concern I would be sure and build boxes that are GG'd for any recessed lights (or anything else that goes through the ceiling to be honest). It's amazing how much sound goes through a little hole. Or rather how much sound is blocked by the GG'd drywall and lets you pinpoint the sound through the leak more easily (hard to say -- the reason I say this was my brother was on the other side of a wall in a garage attic space and the only way I could communicate with him was to shout through one of my power outlet boxes, there was little to no sound anywhere else).


Okay, having pointed out all the things to be aware of and avoid I would also like to add the following:

I LOVE MY GREEN GLUE INSTALL!!

That's right, even with the minor problems I still have, I cannot believe how great it works. Especially if you consider that you go to all this cost and effort and can't really test it until the room is half way done (or about 75% in my case). I was quite nervous that all this effort (and money) was being put into my dream theater and the big question always loomed: Would I be able to watch movies and TV and sound levels I like without having my wife come pounding on the door late at night yelling at me to turn it down?!

The answer (which I learned only a couple of weeks ago) is YES. I can watch movies at my preferred sound levels (which is nervous loud -- I still worry she'll come banging on the door which is what always happened in the past) yet every morning I ask her if she heard anything the night before and she didn't. Nor do the kids wake up on the rooms beside the theater.

Sunday evening I had my family over for a quick sound/picture demo and in the middle of oohing and aahing over the Master and Commander battle scene and the Incredibles island fight scenes (with the kids) my brother came in (who's had plenty of viewing time before so knows how it sounds inside) made my favorite comment of the night: "Dude, I couldn't even hear it at the top of the stairs and could barely hear it outside the door!" SWEET!

So yeah, spend a little more time and effort to close up those last holes/leaks and you'll be happy as can be!

Mike

Mike, th at's awesome.

And great tips for everybody.

One tip for outlet boxes are to not have them "back to back", but always in different stud cavities, and insulate the cavities that contain them (outlet boxes).

mmattia,

Oak doors are a lot of mass, obviously. Seals would be your first priority. Seal them and perhaps try them before doing anything else.


yep, seals on the doors are the first thing to worry about.

with respect to treating the floor (Kevin's comments), i would not say that i'm not a fan of floating floors... I remember that debate, and as i recall i had alot of trouble being clear in my posts, which was too bad. :o

First, Teds advice is (as usual) solid. However, of course, as the level of isolation in a room goes up, you will find a time when improving sound transmission through the slab becomes necessary... And i am not against floating floors, i just caution that alot of the calculations involved with floating floors aren't accurate. And a 1" fiberglass layer with some plywood over it... that system will yield a higher resonance point than is really ideal (or good) for a theater.

Different systems of floating floors will behave differently, and regrettably there really isn't a lab out there to actually test flanking via a slab (as far as i know). The NRC has done alot of work on flanking through higher floors, but i don't know of any via the slab.

Such a lab could be built, but would have very limited utility (really only being good for just this test), and i suppose the gain doesn't justify the cost. A large empty basement could be temporarily used successfully for such a purpose, but that would require 6 or 9 months of a highly cooperative homeowner...

In general, when it comes to floating floors my recommendationsa re to follow the advice of the designer (if you have one), or to post here or email myself or someone with the details, and to discuss the pro's and con's. They can be the greatest thing, and they can be troublesome.


The reason is that decoupling (like a floating floor) only helps at frequencies well above the resonance point... and alot of floating floors (like plywood over fiberglass) won't yield a low resonance point.

I am doing my GG install this weekend. On the site, it is recommended to do between 1 - 3 tubes per 4x8 sheet of drywall. If I used the calculator to estimate cases for full coverage, then how many tubes should I shoot for? I'd hate to start with 3 and run out... then again, I'd hate to have a whole case left over at the end as well.

thanks,
aaron

Hi Aaron,

You would be using 2 tubes per sheet.

Thanks,

Thanks Ted! I also have a return vent high up in my room. On the other side of the wall, I am unable to do two layers.

http://www.hinnispace.com/pictures/theater/rear-right-cavity-medium.jpg

Instead, for this particular stud cavity I put a piece of drywall *inside* of the cavity, almost flush with the edge of the studs(that pic taken before I put the drywall piece in there). I was hoping I could put a layer of GG on that piece, but am wondering if that will work at all since I didn't get it completely flush (maybe 1/8" inset into the cavity). Do you think the 1/8" is too big of a gap?

thanks,
aaron

Hi Aaron,

If you're asking if the Green Glue will span 1/8", the answer would be no. Green Glue when compressed between two panels is less that 1mm. Consider trimming out that section with 1/8" material. Use a small amount of Green Glue to accomplish this and use screws.

So what happens if it doesn't totally compress? I was wondering if I could just layer it on extra thick on the small piece of drywall and it just get compressed less when they put on the regular sheet.

Thinking about this, I guess what would happen would be that it would get compressed more than I would want it to while they were hanging the drywall, then the drywall would move away from this other sheet leaving air pockets.

I guess I should just redo my hack job and try to get it flush, unless you have any ideas for roughly 1/8" thick material to layer on top of my small drywall piece. I am wondering if I could just layer on some drywall mud to even it out.

Uncompressed Green or overly thick Green won't work well for you. The drywall mud is a GREAT idea, however!

Hello all

I'm new to this forum and thread. But I've been reading it for days now! I think I've read about half of it now. Lots of incredible information... Forgive me for this long post... I'd like your opinion on my ongoing project...

I've started my HT construction several days ago, and I already planned on using gg (I have my 3 cases already, can't wait to start using them). I'm lucky I found this thread before I'm too far in the construction.

My room dimensions are about 11.5 x 15.5 feet. I currently have a ceiling height of 10+ feet but that's part of one of my questions. The room is actually the back-end of my garage (which I do not use), so it's cement slab on the floor and about 12" high on 2 walls (see picture IMAGE_00014.jpg). The rest of these two exerior walls I'm not exactly sure how they're made, but it's minimum 2x4 (probably 2x6 if not even 2x8) with 16" stud spacing with good insulation & vapor barrier (I live in Quebec city, Canada, it gets real cold during winter), and normal 1/2" drywall over the assembly. My current plan is to green glue 5/8" 'firecode' drywall over them. I see in this thread that the preferred way is 5/8 first then 1/2... I just can't afford to remove all the existing one just to switch, unless there is really a problem with this. Feedback please?

I have two new interior walls to divide the garage space in both length and width. You have to understand that there is the front-end of my garage on the other side of one wall, and then a hallway or more like a corridor for various storage on the other side of the second wall. The rest of the house is about 6-10 feet away and separated by a very thick wall (just like if you'd add the garage to the house after the house was built) with about a third of the height being cement. Even right now, it's somewhat difficult to hear someone shout while being in the garage when standing in the main entrance of the house.

These two new walls are 2x4 normal stud (not staggered) 12" OC spaced. See pictures 15 and 16 for more details. I've placed a very flexible foamy band on all studs both inside and outside the room. The outside is already drywalled with 1/2" over this tape. I think it's already better than usual drywall directly over studs. I can see the foam tape is not compressed to the point where it has no more effect (I can see the compression by pushing on the drywall). Knocking on it gives a more silenced "thud" than on a regular wall. But I'd like to get your feedback on this. I didn't know before that you could put gg over the studs.

Then, for these two interior walls, I would end up with (from the outside to the inside):
1/2" drywall -- foam tape -- 2x4 studs filled with safe'n'sound insulation -- foam tape -- 5/8" 'firecode' -- gg -- 1/2".

Oh and by the way, I'm putting acoustic caulk on the sides of every drywall panels and also on the corners, so there should be no leakage there.

Now, for ceiling, I was first planning for a drop ceiling with good acoustic tiles... But reading this thread made me realize I should "drop" the idea, not the ceiling ;)

Like I said before, I have plenty of room height (picture 15). There will be a lower ceiling box all around the room (about 16" wide) - is this what you call "sofite" here?. I was planning on putting the drop ceiling at about 8-9 feet, leaving me with more than 1 feet of empty air between it and the current ceiling. Also, I'm on a tight budget so I don't know if I'm ready to go down the path of clips and hat and all... Could I simply build a new ceiling structure at 8' strong enough to handle the same design as my walls? With the 1-2 feet of air between the new ceiling and the current one, would it provide good isolation?

One last thing regarding the ceiling. On the top of my HT room, there is two things... About a third of it is a roof (cause the second floor does not go as far as my garage does) - all right, nobody to disturb there (but the idea is still to keep all the sound inside the room, right?) - and the rest is the guests room. BUT... there's also my washer and dryer machines in there. Obviously, I do not plan on using them while I watch movies, but still... you never know.

--- EDIT: Why then do I read that acoustic tiles are a good use for acoustic room treatment here: thread number 255432 of this forum. Do you use both?!?!?

Finally, for the floor, since it's a garage slab, it's not level (there's a drain right in the middle of it), so I have to build a floor structure over it to make it level. Also, there's nothing under the garage. I was planning on first putting somekind of acoustic matt all over it and build my structure over the mat. Then regular plywood, the undercarpet thing and a nice and thick carpet. I am also planning on making sure the whole floor structure does not touch my walls, to decouple it. Your ideas on the whole thing?

I'd like to know if I'm doing things correctly and if there is anything I should change or do or add or whatever, to make sure I do not loose my investment by forgetting something I don't even know about!!!

Thank you VERY much for all of your help. Sorry for this long long post... can't believe it myself.

Guy

We completed the GG install over the weekend. Things went well, and this stuff is pretty easy to put on. I was careful to not get much on me, but the drywallers... not so much.

Anyway, some got on one of the ceiling pieces. I rubbed it off, but it is still visibile, and sticky. Is there a good way to clean it off of the drywall, or should I have them put a layer of mud over it, or will primer take care of it?

Suggestions?

thanks,
aaron

I ended up wetting a rag, and squirting some Goo Gone on it, and rubbed the GG off of my drywall. Unfortunately, it also rubbed off some of the paper. Fortunately my mudder had to show up today to do some sanding, so he is just gonna slap a thin layer over my minor destruction.

Has anyone compared the STC of a 5/8" Drywall Green Glue sandwich to a Cement board Green Glue sandwich ??

Has anyone compared the STC of a 5/8" Drywall Green Glue sandwich to a Cement board Green Glue sandwich ??
I haven't, but would be surprised if GG wasn't just as effective. Brian at the GG Company would be the expert on this, of course. Cement board is maybe twice the density of drywall, but is thinner and probably has different mechanical properties. But if it can vibrate, then viscoelastic damping should work to absorb such vibration.

Regards,
Terry

Did I scared everyone with my long message?

See post #827 above...

Anyone daring to try an answer?

Thanks...

Did I scared everyone with my long message?

See post #827 above...

Anyone daring to try an answer?

Thanks...

Sure, 5/8"-GG-5/8" is preferred, but if you've already got the 1/2" up, I wouldn't rip it out.

Any reason you don't want to use your full ceiling height for the theatre? Yes, the lowered ceiling "box" is a soffit.

I haven't read the whole acoustic thread you referenced, but acoustic tile may be good for acoustics, but not good for sound isolation. It's two different objectives. Newbies confuse the two all the time :)

GREAT thread and forum! (thanks Google) :)

Anyway- I have been doing some research the past couple days on soundproofing, so please excuse me for any nOoBism I may display...

My situation:

I have recently leased a nice new shop for my sign business. Nice new metal building, even has radiant floor heat. There are 4 shops all side by side here, with 3 interior wall partitions separating them. Unfortunately, they are just hollow 2x4 walls! There is not even fiberglass insulation inside the stud cavities. SIngle layer of 5/8in firecode drywall on each side. As you can imagine, the sound transmission is HORRIBLE. Speech at normal levels can EASILY be understood.

Anyway- the owner realizes there is a problem and agrees that something should be done. He suggested blowing cellulose insulation inside the walls, which I was almost ready to start until I decided to research this some more to see what kind of benefit we would see from this. The 2 walls in my shop are 44ft long x 18ft. There is 2x4 fireblocking every 6ft, and stus are 16in on center. I would have to drill app. (99) 3in holes in EACH wall; hope that the celulose blows all the way down like it should; then patch every hole! :eek:

I decided to call "Scott' from "Sound Proofing America" and he told me all about the "Green Glue". Although we have not purchased the Green Glue yet, it does seem like the best solution (with new layer of 1/2in drywall on my side of the walls). We'd need 150 tubes at 3 tubes per sheet= lots of $$!

I did read up on their website and looked over some comparisons, etc. I guess my main questions and reason for posting is:

-What exactly is the key product in GG that makes it work SO well- rubber? If so, wouldn't a thin layer (sheet) of rubber work just as well (or close to) as the GG? For instance- there is EPDM on ebay in all different sizes. After freight, we're talking about $.50 per sq ft, and it's 45mil. It would be MUCH easier (and less mess!) to hang a full sheet of this on the existing drywall and then rock over it.

Sorry for the rambling- I just want to get some unbiased opinions on whether or not there are any comparable products out there that would save us some money!

Thanks-
Rog

-What exactly is the key product in GG that makes it work SO well- rubber? If so, wouldn't a thin layer (sheet) of rubber work just as well (or close to) as the GG?
The short answer: no. Rubbery stuff typically has a low loss factor -- it bounces more than it dampens energy. Viscoelastic materials are specifically engineered to have a high loss at the desired operating temperature and frequency range.

- Terry

Buy it you'll be amazed, I put 3 layers of 5/8 in my theater each layer has the optium GG in between.

Just started using my GG supply yesterday and got a few spatters on my face and hands. Don't ask. I tried to wash it off with soap but had no luck. Asked my Chemical Engineer wife what to do and she gave me the best tip. I thought I'd pass it on to you since it worked so good.

To remove GG from your skin, rub some olive oil or vegetable oil into the affected area. Then wash with soapy water. The oil mixes with the adhesive in the GG and pulls it up from your skin and the soapy water takes both off. It worked great! :D I didn't wait for it to dry by the way. I don't know how effective this is if you don't do it strait away.

She doesn't recommend using citrus based solvents on your skin.

Craigo

rub some olive oil or vegetable oil into the affected area
Yum - sounds like a nice sandwich - layers of drywall on the outside, GG as the filler & a little olive oil for flavor....

Just need a little help finishing up my green glue install.
What have you guys done with your equipment racks which attach to another room?

What can I do to prevent this from being a major weak point in the room.

Mine isn't attached to another room, but wouldn't you just line that room or closet with another layer of drywall and GG as well? To keep the sound in, you gotta do it all.

Craigo

Is the AVS discount on Green Glue still valid? I tried a couple of things in the "coupon code" field including "AVSFORUM" to no avail.

I'm going to order a couple of cases, and the discount amounts to a good chunk of the shipping.

SC

Is the AVS discount on Green Glue still valid? I tried a couple of things in the "coupon code" field including "AVSFORUM" to no avail.

I'm going to order a couple of cases, and the discount amounts to a good chunk of the shipping.

SC

I just ordered 6 cases on Dec. 6 and received the discount. Did you try AVS Forum?

Yeah, I tried every combination of case and spacing I could think of. I get:

You have entered an incorrect coupon code !
This coupon does not exist, has been disabled or has expired.

Please contact administrator and report the error(s).

Let's see...it was the 15th yesterday, so with my typical luck, that means the discount expired 12/14.

SC

Yeah, I tried every combination of case and spacing I could think of. I get:



Let's see...it was the 15th yesterday, so with my typical luck, that means the discount expired 12/14.

SC

I would e-mail them and ask, that's what I did.

I just placed an order for five cases and the discount was applied without any problems.

Does anyone know the amount of green glue that should optimally be used between the three plywood layers of my proscenium? and also should I use GG between the layers of my riser, which will support two seats and a buttkicker LFE. I only have three tubes of GG left...I wil probably have to order a few more...

Does anyone know the amount of green glue that should optimally be used between the three plywood layers of my proscenium? and also should I use GG between the layers of my riser, which will support two seats and a buttkicker LFE. I only have three tubes of GG left...I wil probably have to order a few more...

I've heard of using GG or roofing felt in between the stage layers. This why so many layers on a stage thread (http://www.avsforum.com/avs-vb/showthread.php?t=706036) might give you some more insight. I would suspect that you would use the same amount in between stage layers as you would in between drywall layers. If you just have three tubes left, and don't want to order more, I would probably use them between one of the stage layers, and use roofing felt between everything else.

If you're not putting in new ceiling joists and still trying to isolate with furring strips and drywall, GG, drywall on the ceiling and building new 2x4 walls 24'" OC with drywall, GG, drywall, would you put anything between the new walls and the existing ceiling joists when you nail them together?

Randy D

hey Randy, PAC and kinetics make products taht are designed to stabilize walls without attaching them to the ceiling. So they would keep the ceiling joists out of rigid contact with the lower walls.

I can't speak to how effective they are, as its devilishly hard to find an opportunity to run a "with" and "without" test. No lab for that test exists as far as i know, and nobody has volunteered to build their basement, then rip it apart, then build it again.

My advice is this: go ahead and use them if you desire, but if the $$$ or time is a concern to you, i have no problem recommending not using the products. The reason for that is that with GG in t he stud wall below, so much less energy will be transferred up to the joists than in a conventioanl wall that alot of the gains will already be had. Also, its my anticipation that it will be mostly high/middle freqs where seperating stud and joist benefit you.

But again, often in post i can say that i "know" the answer from running gadzook loads of tests, but in this case i offer an educated guess.

Thanks, Brian. I hadn't seen much discussion about separating the ceiling joists from the lower walls in the 29 pages of this thread (other than going with a separate set of joists) and I was hoping it wasn't crucial to do so.

I would like to build a dedicated home theater in a corner of my unfinished basement. The area is roughly 20' by 13' by 7'8" and has adjacent outside concrete block walls. The main support beam is made of 3 2 x 10's sandwiched together and runs parallel (and about 13' from) the long concrete wall. I'm having a problem with where to put the long interior wall. There are two round metal posts supporting the beam that would interfere with putting drywall on the outside of the wall if I construct the wall just inside the beam. Would it make sense to build boxes (columns) around the posts and then build the wall in sections between the columns. Is it advisable to build a wall under the main beam?

Thanks, Brian. I hadn't seen much discussion about separating the ceiling joists from the lower walls in the 29 pages of this thread (other than going with a separate set of joists) and I was hoping it wasn't crucial to do so.

I would like to build a dedicated home theater in a corner of my unfinished basement. The area is roughly 20' by 13' by 7'8" and has adjacent outside concrete block walls. The main support beam is made of 3 2 x 10's sandwiched together and runs parallel (and about 13' from) the long concrete wall. I'm having a problem with where to put the long interior wall. There are two round metal posts supporting the beam that would interfere with putting drywall on the outside of the wall if I construct the wall just inside the beam. Would it make sense to build boxes (columns) around the posts and then build the wall in sections between the columns. Is it advisable to build a wall under the main beam?

just some thoughts: you could build behind the beams and drywall around them to make columns.

If one side of the wall is continuous drywall, and the other side has a protruding part for the beam, it should work fine.

I do apologize, but i sometimes have trouble picturing things and a sketch of the beam part of the wall would help.

If the 2x10 beam is exposed at the top of a wall (not shielded by a wall/ceiling joint or something), that will leak alot of sound, and covering it would be a good idea.

Was curious about one thing with green glue, how does it age? For example will it still have the same sound properties 10,20,30 years from now?

it ages very, very well. it will outlast the sealants you would use to seal the wall. in 10, 20, 30 years a much more likely cause of isolatio failure would be fractured seals from a shifting house (or earthquake, etc.).

I'm afraid (joke, its good in this case) that in 30 or even 50 years it will still be sticky. :D

good to hear, thanks!

OK...I'm close to drywall. My ceiling is about 15 sheets (single layer) but has about 15 ceiling cans installed. Is GG really going to do a lot with this many ceiling cans, or will it just be overkill?

OK...I'm close to drywall. My ceiling is about 15 sheets (single layer) but has about 15 ceiling cans installed. Is GG really going to do a lot with this many ceiling cans, or will it just be overkill?

I can only offer an educated guess in this case as we haven't yet experimented with cans in a ceiling. That (outlining the effect of ceiling cans in a formal lab environment) is something that we'll get done this year, and if you aren't building right away you might benefit from those tests, although i can't yet say exactly when they'll happen.

If you have to build sooner than that, i can offer this educated guess.

The cans will be more of a higher frequency problem than low-freq. 15 cans won't remove all that much mass from the ceiling in the grand scheme (a few pounds out of a ceiling that would weigh 1000 pounds or more), and low frequencies don't readily pass through even wide-open holes that are that small (like a can that's a few inches around) because their wavelengths are so huge.

So the benefits of GG at low freqs should still be intact.

At higher freqs, its harder for me to guess what the impact of the cans will be, put if there is insulation above the cans in the cavity,a nd if the floor layer is sealed (caulk the floor/joist and floor/floor seams before drywalling),a nd if the cans themselves are sealed, its my anticipation that the inclusion of cans won't have all that much of a negative effect.

Again, that is only my anticipation and i haven't tested it.

Brian,

It seems like it'll probably be best to build the wall inside the beam. I don’t know how to sketch it, but the wall would run parallel to and up against (no small spaces, right?) the beam for the full length of the wall. I can cover the inside of the wall with 2 layers of drywall and GG from floor to ceiling. On the outside, the upper 9¼” would be the wood beam that is 4½” thick, and the lower portion would be 2 layers of drywall sandwiched with GG. The wall cavity will be filled with fiberglass. I’ll just have to box around the 2 round, metal support posts that will be in the way on the outside of the wall. Building the wall on the outside of the beam would be a problem because the main furnace duct, some plumbing, and electrical wiring run parallel and close to the beam on that side.

The other interior wall (the short wall that will be the screen wall) also presents a problem. The stairway to the basement is the boundary of the home theater space on that end and runs parallel to the location of that wall. I plan to leave a small space (inches) between the outside of the wall and the stairway and the are under the stairs is open, but it seems that it will be hard to put up drywall on the outside of the wall with the stairway in the way. How do you attach drywall to the outside of a wall in areas where space is limited?

Randy D

Brian,

It seems like it'll probably be best to build the wall inside the beam. I don’t know how to sketch it, but the wall would run parallel to and up against (no small spaces, right?) the beam for the full length of the wall. I can cover the inside of the wall with 2 layers of drywall and GG from floor to ceiling. On the outside, the upper 9¼” would be the wood beam that is 4½” thick, and the lower portion would be 2 layers of drywall sandwiched with GG. The wall cavity will be filled with fiberglass. I’ll just have to box around the 2 round, metal support posts that will be in the way on the outside of the wall. Building the wall on the outside of the beam would be a problem because the main furnace duct, some plumbing, and electrical wiring run parallel and close to the beam on that side.

ok, i got it. the beam area will leak more mid/high freq than the rest of the wall but low-freq through the beam area should be good. Overall, it shouldu work well.

If, after assembly, you find that the beam area on the back is a big sound leak you could add drywall or just absorption over it to help with those mid/high frequencies, but i doubt this will ultimately cause you any trouble at all.

The other interior wall (the short wall that will be the screen wall) also presents a problem. The stairway to the basement is the boundary of the home theater space on that end and runs parallel to the location of that wall. I plan to leave a small space (inches) between the outside of the wall and the stairway and the are under the stairs is open, but it seems that it will be hard to put up drywall on the outside of the wall with the stairway in the way. How do you attach drywall to the outside of a wall in areas where space is limited?

Randy D

Randy, for that question i really don't know.

Perhaps you could set it up like this (im' picturing a crawl space under the stairs): fill a decent chunk of the space under the stairs with absorption (boring old low-cost fiberglass), caulk the stairs if necessary, and simply leave that front side of the wall with drywall only on the inside. You could drywall around the stairs as needed... ?

If that won't work there is always a way to find an answer, its just an idea i had.

Brian,

Thanks for the response. I'll have to think some more on that problem wall. I had planned to put my home theater equipment under the stairs, but not coupled to the theater area (except for wire conduit, perhaps). I though it would be a bad idea to have the stairs in contact with the theater room walls, so I thought I'd build the wall in a couple of inches from the stairs. I may be able to slide drywall in somehow and then screw it to the outside of the wall while kneeling on the stairs or crouching under the stairs. May only get one sheet of drywall on that side, though. Could get pretty messy trying to slide a sheet w/GG on it.

Randy D

Have an addition which includes 23X15 X10(H) theater under construction. Applied two layers of drywall (1 5/8 and 1 1/2) with Green Glue at 100% application.

The existing house is 80 Years old, and is uninsulated and single pain windows. (thank goodness for moderate weather). As I lay in bed at night in existing house I can hear much outside noise (cars, etc) and especially aircraft as we are on the approach end of a GA airport, and we are about three blocks from an elevated train (BART), which I also here when the train goes by.

Immediately after installation of the drywall and GG in the theater I went out into the theater in the evening and shut everything off and listened. Mostly quiet, but could barely here only the BART trains and GA Aircraft, though much quieter.

About two weeks later redid the test. Now I here nothing. No trains, no airplanes, nothing. Listened for about an hour, and heard nothing. Haven't heard anything in the theater other than noise I created for a month now. Couldn't be happier.

Allen

I had a question about the GG acoustic tests that were done. The "standard" double-wll setup shows two separated walls with double drywall and GG on each side. We're the tops and bottoms of the wall sealed against concrete?

I ask because while I do not doubt the efficacy of DD + GG for the interior walls of the HT, I'm debating whether it does much good for the exterior walls in a basement setup. One noise inside the theater passes through the DD + GG on the wall (or the ceiling), it enters into the floor joist space, which contains only insulation. From there sound can pass to the rest of the house without ever coming down between the walls and passing through the second layer of DD + GG. Does this make sense? Would I be better served by putting a 3rd layer of drywall with GG on the ceiling rather than a second layer on the outside of the double wall?

Have an addition which includes 23X15 X10(H) theater under construction. Applied two layers of drywall (1 5/8 and 1 1/2) with Green Glue at 100% application.

The existing house is 80 Years old, and is uninsulated and single pain windows. (thank goodness for moderate weather). As I lay in bed at night in existing house I can hear much outside noise (cars, etc) and especially aircraft as we are on the approach end of a GA airport, and we are about three blocks from an elevated train (BART), which I also here when the train goes by.

Immediately after installation of the drywall and GG in the theater I went out into the theater in the evening and shut everything off and listened. Mostly quiet, but could barely here only the BART trains and GA Aircraft, though much quieter.

About two weeks later redid the test. Now I here nothing. No trains, no airplanes, nothing. Listened for about an hour, and heard nothing. Haven't heard anything in the theater other than noise I created for a month now. Couldn't be happier.

Allen

Allen, that sounds awesome. :)

I had a question about the GG acoustic tests that were done. The "standard" double-wll setup shows two separated walls with double drywall and GG on each side. We're the tops and bottoms of the wall sealed against concrete?

do you have a link to that picture?

In lab tests at Orfield, the top and bottom plates of all the walls are against steel that is adhered to concrete. The test opening is basically a steel-lined hole in concrete walls and the frames are bolted into the hole through the steel.

At Riverbank Labs removable test partitiosn that are (i think) constructed of steel and lined with MDF are placed into a gap between the concrete rooms with a crane, and the wall framing members are bolted/screwed to those.

I ask because while I do not doubt the efficacy of DD + GG for the interior walls of the HT, I'm debating whether it does much good for the exterior walls in a basement setup. One noise inside the theater passes through the DD + GG on the wall (or the ceiling), it enters into the floor joist space, which contains only insulation. From there sound can pass to the rest of the house without ever coming down between the walls and passing through the second layer of DD + GG. Does this make sense? Would I be better served by putting a 3rd layer of drywall with GG on the ceiling rather than a second layer on the outside of the double wall?

Kevin, i face my basic mental problem of visualizing peoples descriptiosn pretty poorly again.

You ask (correct me if i'm wrong) if 3 layers of GG on the ceiling would be preferable to 2 layers on the ceiling and 2 layers on the studs away from the foundation / exterior?

Could i ask before offering an answer, what the exterior wall construction is, and what the ceiling construction is,a nd if the air cavity of the exterior wall is connected to the ceiling air cavity?

Thanks for the reply, Brian. I realize that visualizing people's layouts from text is hard.

do you have a link to that picture?

I was referring to the double wall picture from your website. shown here (http://www.greengluecompany.com/usingGreenGlue.php ) under "drywall choice recommendations by wall type" and described in this report (http://www.greengluecompany.com/images/transmissionLossTests/OL05-0414_Report.pdf )


You ask (correct me if i'm wrong) if 3 layers of GG on the ceiling would be preferable to 2 layers on the ceiling and 2 layers on the studs away from the foundation / exterior?

I'm asking if 3 layers from drywall with GG on the ceiling (on RSIC clips) would be better than 2 laters on the studs on the exterior side of the wall. (Assume interior is the side facing the HT and there is no foundation wall involved.)

Could i ask before offering an answer, what the exterior wall construction is, and what the ceiling construction is,a nd if the air cavity of the exterior wall is connected to the ceiling air cavity?

Interior and exterior walls are both 2x4 studs, 24" OC. Bottom plate is glued/screwed to a concrete slab. The top plate of the interior wall is connected to engineered joists via DC-04 clips. The top plate of the exterior wall is nailed to the joists (both walls perpendicular to the joists, for sake of argument). So yes, the air cavity of the exterior wall is connected to the ceiling air cavity. Once sound passes through the ceiling of the theater, it enters the space in between the joists (which are open in both the x and y places) and can travel freely throughout the basement, bypassing the exterior wall. If it helps, I made some crude drawings of the type of wall in question.

Kevin,

nice sketches. i like word as a sketch tool, sometimes it can be pretty fast.

in your case i would opt for double drywall on the ceiling, and on the walls, rather than triple drywall on the ceiling. The reason is that those exterior walls (sheathing/single drywall) will be quite resonant and could inject a good dose of flanking noise into the rest of your home.

Additionally, as the top plate of the exterior wall is firmly connected to the joists, the damping on that wall will cut down on flanking noise at other freq's (not just the low-freq resonance) by dissipating energy as it travels up the wall.

So in this case i recommend ceiling + walls, and not just a super-celing, Use 50% GG on the ceiling if you need to keep overall use down.

Brian

Thanks again for the response, Brian. Cost of the GG isn't a big issue - I'm willing to spend what it takes to have as good of a performing room as I can. I'm planning on living here until I die, so I might as well do it right the first time. (That said, like most people I'd rather not throw away money on something that isn't going to help.)

For clarification, I was planning on doing GG on the interior walls all along, just debating wether it wass doing much good on the "outside" of that wall since there is a 1" gap in between that leads up into the floor joists. I guess that what you are saying is that that 1" gap at the top plate is a lot smaller area than the ~8' height of the wall. And I suppose it could at least be plugged with insulation.

Regardless of walls, where would you say the point of diminishing returns is on the ceiling? Certainly 3 is better than 2, and 15 is better than 3, but at some point it stops getting much better for your money and other flanking paths provide greater problems. I realize that "value" is highly subjective but I'm just curious if it were you
r room how many layers you would put on the ceiling.

Kevin ... adding additional layers of drywall is helpful; but, as you observe, with diminishing returns. On the other hand, a super ceiling along with semi-super walls is a non-starter. It doesn't matter where you put the hole in the aquarium, the water's is still going to leak out.

Quick question. I have a dedicated room under construction. 25x17x11' three of the walls are exterior. Do you thinks it's wise to do double layer on the exterior with GG? That would help keep out the outside noises.

For the interior walls I was thinking about double layer drywall 5/8" and 1/2" with GG. I was also doing the same with the ceiling which has my daughters closet above.

My current interior walls are double walls not touching with MLV in the exterior wall, however I know its not properly sealed and there are breaches like electrical boxes, etc

Thanks
Chris

Thanks again for the response, Brian. Cost of the GG isn't a big issue - I'm willing to spend what it takes to have as good of a performing room as I can. I'm planning on living here until I die, so I might as well do it right the first time. (That said, like most people I'd rather not throw away money on something that isn't going to help.)

For clarification, I was planning on doing GG on the interior walls all along, just debating wether it wass doing much good on the "outside" of that wall since there is a 1" gap in between that leads up into the floor joists. I guess that what you are saying is that that 1" gap at the top plate is a lot smaller area than the ~8' height of the wall. And I suppose it could at least be plugged with insulation.

Regardless of walls, where would you say the point of diminishing returns is on the ceiling? Certainly 3 is better than 2, and 15 is better than 3, but at some point it stops getting much better for your money and other flanking paths provide greater problems. I realize that "value" is highly subjective but I'm just curious if it were you
r room how many layers you would put on the ceiling.

I'd still recommend doubling the exterior walls -vs- tripling the ceiling.

When it comes to diminishing returns and walls, three basic factors come into play.

The first (but not most important) is redundancy of damping layers. Diminishing returns sets in very quickly after 2 layers of Green Glue, and it is generally cost-sensible to reduce the coverage on more than 1 damping layer. For example, if you added a third layer of drywall, there would be quite a small difference between 2x100% coverage with Green and 1x100% + 1x50%, etc.

The second (and most important) thing that creates diminishing returns situatiosn is flanking noise. At some poitn - even in labs - more noise will bleed through concrete and ducts and doors and strange little paths its hard to track down than through the wall. For example - despite their massive concrete floating on springs construction - i am aware of only one lab in the Western Hemisphere that can test STC values higher than 75 (the NRCs lab in Canada) and only a very small number of such labs exist in Europe, etc.

The third factor is perception. At some poitn you will not have a nosie problem and you can safely declare things "good enough", and adding more to that will be diminishing returns to you even if a mic and analyzer still report big gains.

And fourth (i know i said only 3 but i'd forgotten about perception) is mass. To understand how adding mass becomes progressively less effective consider taht if you have one layer of materialX and it got an STC of 30 as a simple panel, you would expect 2 layers to get 36, 3 layers to get 39, 4 layers to get a 42, 8 layers 48, 16 layers 54, etc. Each layer brings less to the table than the ones before it.
It isn't that simple in damped or decoupled walls, by the way, but diminishing returns will still apply.


For an answre to your question, beyond the 2nd layer of drywall you will start to run into flanking noise limitatiosn in most homes, and beyond the 3rd layer of drywall (provided flanking isn't a problem), you'll just hit diminishing returns.

That noted, Kevin, if budget isn't an issue (and run this by PAC to ensure that you get enough clips to support the load) adding a 3rd layer to your ceiling and double drywalling the rest of your room isn't at all a bad idea.

Quick question. I have a dedicated room under construction. 25x17x11' three of the walls are exterior. Do you thinks it's wise to do double layer on the exterior with GG? That would help keep out the outside noises.

if the $$$ aren't a deciding factor, then yes absolutely.

For the interior walls I was thinking about double layer drywall 5/8" and 1/2" with GG. I was also doing the same with the ceiling which has my daughters closet above.

My current interior walls are double walls not touching with MLV in the exterior wall, however I know its not properly sealed and there are breaches like electrical boxes, etc

Thanks
Chris

Chris, for double walls (decoupled), id' recommend all 5/8" drywall, but adding mass & damping to double stud walls (or any decoupled wall) yields great returns.

Brian,

Thanks for the reply. One question is I will be having recessed lighting in the ceiling. Also I will be having inwall speakers for my surrounds. What do you think I should be doing to help keep the integrity of the sound proofing in tact?

Also for the exterior walls, do I need GG or will double 5/8" drywall be sufficient

Thanks again
Chris

I have seen people build boxes where the lights and speakers will be. For lights you need to ensure you get the cans built for placing in cavities where insulation will be. For the speakers you need to be carefull you don't restrict the volume behind the cone. I know not much help, but hopefully someone else will have some more info.

Thanks again to both Brian and Dennis for chiming in here to my questions. Sounds like the recommendation is definitely for GG on both sides of the walls and probably just stick to 2 layers on the ceiling since there invariable be a weaker link in the system somewhere.

As Dennis mentions, the water will come out wherever you poke a hole into the aquarium, and unfortunately it is necessary to poke a hole in it. Even with a separate HVAC system (minisplit or somesuch), you need fresh air into the theater somehow to prevent CO2 levels from reaching uncomfortable levels. I was planning on building a couple baffle boxes with SilenX fans to add/remove air, but that will still probably be a better sound transmission path than the ceiling.

The cans will be more of a higher frequency problem than low-freq. 15 cans won't remove all that much mass from the ceiling in the grand scheme (a few pounds out of a ceiling that would weigh 1000 pounds or more), and low frequencies don't readily pass through even wide-open holes that are that small (like a can that's a few inches around) because their wavelengths are so huge.

So the benefits of GG at low freqs should still be intact.


So when does an LFE wavelength find a flanking path to its liking? Or how big a hole can you get away with? Would flex duct be onesuch path?

I am trying to build as good a mousetrap as I can, but the devil is in the detail. Based on this, I am inclined to let a few sealed cans penetrate the ceiling, probably with backer boxes. Handling the CRT mount, the HVAC, and whatnot are still tough.

Brian,

Thanks for the reply. One question is I will be having recessed lighting in the ceiling. Also I will be having inwall speakers for my surrounds. What do you think I should be doing to help keep the integrity of the sound proofing in tact?

Also for the exterior walls, do I need GG or will double 5/8" drywall be sufficient

Thanks again
Chris

Chris,

with respect to the speakers, i would build a box around them as its always troublesome to inject noise directly into a system.

For the lights, i've not yet had time to generate test data to give concrete answers, but based on some informal data involving holes in partitions, i think that if you

1. don't use more lights than you need to. less is more in this case
2. smaller is also better
3. make sure they are sealed
4. make sure there is insulation in the cavities above the lights
5. it is a good idea to also seal the floor/joist level if there is any reason to believe its not sealed (usually floors, with their coverings and all, aren't leaky like walls, but stranger things can happen)

the lights won't "break the bank" with respect to sound control. Its also my anticipation that the biggest problem will be at higher freq's.

Ted White of GGCo knows of a light that he thinks has some good potential for theater ceilings and if he sees this perhaps he'll chime in.


For the exterior walls, i would recommend sneaking some GG out of other areas of the theater to put it in the exterior walls rather than leaving the exterior walls bare. This better approaches the ideal of having all sides of a room "good" to avoid flanking issues.

So when does an LFE wavelength find a flanking path to its liking? Or how big a hole can you get away with? Would flex duct be onesuch path?

I am trying to build as good a mousetrap as I can, but the devil is in the detail. Based on this, I am inclined to let a few sealed cans penetrate the ceiling, probably with backer boxes. Handling the CRT mount, the HVAC, and whatnot are still tough.

Dave,

that's a great question, and one that i cannot answer concretely. But i can offer a variety of tests and illustrations from labwork at Orfield, some of which were surprising to me. I would ask everybody at AVS to treat this data cautiously, as while the data implies some amount of seal failure can be tolerated, especially at low-freqs, it is more than possible to attain total failure over seals. Seals are critical, critical, critical.

In the first diagram you see a steel stud wall, then the same wall with a 2" hole punched on each side of the insulated cavity. The effect was not great. Thats an open 2" hole.

darn, out of time, will try to enter more later.

but this is perhaps the most comprehensive study on the effect of outlet boxes (similar to light cans) around: http://irc.nrc-cnrc.gc.ca/pubs/ir/ir772/ir772.pdf

take a close look at the graphs, and you will see that you can create some big high freq problems, but generally speaking low-freqs aren't affected.

That study implies that lighting cans are not necessarily a problem, but could be. the steps i outlined above should ensure good results, but i have never actually tested a ceiling with cans. I will, though, sometime this summer.

Thanks Brian, I forgot to mention that the speakers i am going to use are sealed speakers in a cabinet. They are the Triad Gold's. So I woul dthink that by maing sure the area around them is tight, I should not have a problem.
Right??

Right??
No. Not a good plan.

Hello,

I recently purchased 3 cases of GG knowing that I was going to be using it somehow in our dedicated theater room. It's a new home with the "theater room option" built over the garage but it is far from being designed well for sound (I cranked up a cheap bookshelf system in it and went all around the house and can hear it everywhere)

The room is 20x25x10 with 2 exterior and 2 interior walls. The interior walls are next to our kids bedrooms and above the room is an attic. I would like to be able to watch movies and listen to music in the evenings without worrying about waking everyone up. I know that the first step is dealing with the hollow core double door entry (plan on getting solid core double doors with threshold and weather stripping) and after this I want to go the route of an additional layer of drywall over the existing, insulated walls but am not sure if need to treat all the walls. I have the following questions:

1) Would my efforts be wasted if I left the 2 exterior walls and ceiling untreated (since they essentially face "outside") or will flanking be a big issue that would ruin any effects from treating just the interior walls?

2) Will treating the floor with subfloor+GG+plywood make a big difference for sound transmission through the rest of the house or does the fact that it is built over the garage eliminate the need for this?

3) Is there a recommended plan (using only the addition of GG and another layer) other than treating all 4 walls, ceiling, and floor, that will still get decent isolation that will make it worth my efforts?

thanks,
Ed

...
1) Would my efforts be wasted if I left the 2 exterior walls and ceiling untreated (since they essentially face "outside") or will flanking be a big issue that would ruin any effects from treating just the interior walls?

2) Will treating the floor with subfloor+GG+plywood make a big difference for sound transmission through the rest of the house or does the fact that it is built over the garage eliminate the need for this?

3) Is there a recommended plan (using only the addition of GG and another layer) other than treating all 4 walls, ceiling, and floor, that will still get decent isolation that will make it worth my efforts?
Ed,
You are asking some pretty tough questions.

1) Common sense might indicate that the 2 exterior walls may be less of an issue than the others, but one never knows for certain how a particular house will react with regard to flanking. You might try doing the other areas first, and then only treat the exterior walls if you think they still need it -- Tough to tell ahead of time.

2) Even though the room is over the garage, I think that the floor could be a bigger issue than you realize. Depending on how it is constructed, it is likely that the floor joists or other structural members of the floor are directly shared with the rest of the finished portion of your house. Personally, I would do the floor.

3) Is the attic space above the theater shared with the attic space above the rest of the house? If so, I would also treat the ceiling for the same reasons as stated in #2, above.

Currently your door is likely the weakest area and it appears that you have plans for handling that issue. However, another commonly overlooked item that can cause a lot of problems is the HVAC system. If you have ductwork that is shared with the rest of the house, it can ruin an otherwise well-constructed sound isolation plan.

Good luck!
- Scott

Ed,
You are asking some pretty tough questions.

1) Common sense might indicate that the 2 exterior walls may be less of an issue than the others, but one never knows for certain how a particular house will react with regard to flanking. You might try doing the other areas first, and then only treat the exterior walls if you think they still need it -- Tough to tell ahead of time.

2) Even though the room is over the garage, I think that the floor could be a bigger issue than you realize. Depending on how it is constructed, it is likely that the floor joists or other structural members of the floor are directly shared with the rest of the finished portion of your house. Personally, I would do the floor.

3) Is the attic space above the theater shared with the attic space above the rest of the house? If so, I would also treat the ceiling for the same reasons as stated in #2, above.

Currently your door is likely the weakest area and it appears that you have plans for handling that issue. However, another commonly overlooked item that can cause a lot of problems is the HVAC system. If you have ductwork that is shared with the rest of the house, it can ruin an otherwise well-constructed sound isolation plan.

Good luck!
- Scott

Scott,

thanks for the response. the attic space is shared although well insulated (not sure if that will make a huge difference).... as for the floor, there are two tiers. the first tier is level with the rest of the 2nd story floor and above part of the kitchen downstairs, the lower tier is essentially the ceiling of the garage.

i'm thinking if i have to choose between treating either the ceiling or the floor, i might pick the ceiling because the subfloor at least will have thick a pad and thick carpet.....

ed

Hi all,

First, let me say this is an excellent forum and website with well informed people. I have learned so much by just browsing the threads.

Unlike most of you, my need for sound supression is not for entertainment purposes. It's so I don't have to hear my neighbors cough, yell at their dog and involuntarily watch a movie with them though the wall. I'm sure they hear me too, but I can only speak for myself here. What makes it worse is that my bedroom neighbors a living room. Those neighbors were kind enough to move their TV to the opposite wall and keep it extremely quiet after 10pm, however it's still annoying. I can't say the same about the livingroom side neighbors.

I live in a 6 year old condo-conversion building. It's a great place, right across the Hudson and NYC. Great amenities and all that stuff. The problem is, the walls are built to apartment standards.

It's neighbor DW | alum. studs | MY DW. I don't think there is any insulation in the walls and it's .5" drywall on both sides.

I've did a lot of research into sound transmission thanks to this website and others on the internet and wanted to get your opinions on some work I plan to do this spring.

1. I have a bulge in my living room party wall, so I planned to remove a little portion of that area and make it flat. The wall is about 15' in length and 9' high. (Bulge is about 4 feet)

Is it worth it to pull my portion of the drywall down, install insulation, 5/8" drywall + GG + 5/8"? Is the insulation worth the cost and time to redo my side of the wall?

2. Would 5/8" DW + GG + soundboard work better? Would the GG be absorbed by the porus soundboard material? I am hesitant about this as it won't add enough mass.

3. What about 5/8" DW + GG + 1/4" MLV + 5/8" DW ?


thank you in advance.

1. I have a bulge in my living room party wall, so I planned to remove a little portion of that area and make it flat. The wall is about 15' in length and 9' high. (Bulge is about 4 feet)I'm not exactly sure what you mean by a "bulge". None-the-less, are you pretty sure that the majority of the sound is being transmitted through the wall itself and not through the ceiling or floor? As long as you are sure that most of the sound is really coming through the wall, I would agree that GG and more layers of DW will help a lot. However, don't set your expectations too high, since nothing that is practically achievable is truly sound "proof".

Is it worth it to pull my portion of the drywall down, install insulation, 5/8" drywall + GG + 5/8"? Is the insulation worth the cost and time to redo my side of the wall? It is hard to say if it would be worth it or not. All buildings and walls are built differently and may behave differently with regard to sound transmission. You won't really know how much better pulling down your portion of the DW will be unless you actually did it both ways and compared the two. If you have the time and money, one of your best options would be to pull down the DW, then build a new wall about 1" inside of the old wall, fill the cavity with insulation, then cover the new wall with two layers of DW with GG in between. This may not be practical and you may not be willing to lose the additional floor space, but it would be one of your better alternatives. Would it be "worth it"? -- I don't know.

2. Would 5/8" DW + GG + soundboard work better? Would the GG be absorbed by the porus soundboard material? I am hesitant about this as it won't add enough mass. NO! Greenglue needs to be sandwich between two solid surfaces. Also soundboard is nearly worthless for sound isolation compared to the other alternatives.

3. What about 5/8" DW + GG + 1/4" MLV + 5/8" DW ?Again, no. GG needs to be between two layers of drywall.

There have been several other similar questions in this forum regarding sound isolation between party walls. If I remember correctly, a couple of them achieved very respectable results using GG and additional DW. I can't recall the specific titles of the threads, but if you do some searching maybe you can find them.

... just my $0.02...

- Scott

Hi all,

First, let me say this is an excellent forum and website with well informed people. I have learned so much by just browsing the threads.

Unlike most of you, my need for sound supression is not for entertainment purposes. It's so I don't have to hear my neighbors cough, yell at their dog and involuntarily watch a movie with them though the wall. I'm sure they hear me too, but I can only speak for myself here. What makes it worse is that my bedroom neighbors a living room. Those neighbors were kind enough to move their TV to the opposite wall and keep it extremely quiet after 10pm, however it's still annoying. I can't say the same about the livingroom side neighbors.

I live in a 6 year old condo-conversion building. It's a great place, right across the Hudson and NYC. Great amenities and all that stuff. The problem is, the walls are built to apartment standards.

It's neighbor DW | alum. studs | MY DW. I don't think there is any insulation in the walls and it's .5" drywall on both sides.

I've did a lot of research into sound transmission thanks to this website and others on the internet and wanted to get your opinions on some work I plan to do this spring.

1. I have a bulge in my living room party wall, so I planned to remove a little portion of that area and make it flat. The wall is about 15' in length and 9' high. (Bulge is about 4 feet)

Is it worth it to pull my portion of the drywall down, install insulation, 5/8" drywall + GG + 5/8"? Is the insulation worth the cost and time to redo my side of the wall?

2. Would 5/8" DW + GG + soundboard work better? Would the GG be absorbed by the porus soundboard material? I am hesitant about this as it won't add enough mass.

3. What about 5/8" DW + GG + 1/4" MLV + 5/8" DW ?


thank you in advance.


Are they steel studs instead of aluminum? Or do you have a situation where aluminum brackets are holding 1" shaftwall?

That is a pretty important difference, if you could get back. Soundboard will not work as well as more drywall for the reason you gave.

I have a problem. My roommate's room and I are connected by a cheap, hollow door. He's an extremely light sleeper with chronic fatigue syndrome and needs his sleep, and it sounds like almost every sound is coming through this door; the main problem being an alarm clock and my snoring ;). We rent, and I was thinking of getting drywall and putting up drywall (2 panels with Green Glue in the middle) across the entire wall. Is that crazy? Or do you think it would work? Any advice on other solutions? We don't need to use the door and can completely block it off.

I'd just replace the door with a solid-core model. That sounds like the weak point. Replacing the door can't be more than a couple hundred dollars. Even if the place is a rental if the work is done right, no one would be the wiser. Just get the same door design.

I am renovating an apartment, and currently have walls at stage where there is plaster, with brick behind. Can Green Glue be applied directly to the plaster, with wallboard on other side, or do I need to screw wallboard to the plaster and then apply Green Glue and another sheet of wallboard?

Thanks

Can Green Glue be applied to a sheet of plasterboard which is then put up onto a plastered wall?
I want to avoid using two sheets of plasterboard.

Can Green Glue be applied to a sheet of plasterboard which is then put up onto a plastered wall?
I want to avoid using two sheets of plasterboard.

From the Green Glue Company FAQ (http://www.greengluecompany.com/faq.php#A.04):

"4. Can I use Green Glue with only one layer of drywall?
No. Green glue needs to be a constrained layer, meaning that Green Glue is sandwiched between to rigid, dense layers of building material. There is no limit to how many drywall / Green Glue layers you can utilize, and performance will improve as the # of layers goes up. You can save valuable $$$ by using slightly less Green Glue in each damping layer if your walls are to have more than 2 layers of drywall. For floors, you can use any common materials (cement board, OSB, plywood, etc.)"

Please forgive me if I am asking a stupid question, but wouldn't the green glue be constrained between the wall and the new layer of plasterboard?

Please forgive me if I am asking a stupid question, but wouldn't the green glue be constrained between the wall and the new layer of plasterboard?

Not a stupid question at all, but you may be better off asking the folks at GG themselves. Ted White from GG is a regular on AVSForum, or you can email them from their website (http://greengluecompany.com). They'll be able to give you the definitive answer.

-drin

I have a problem. My roommate's room and I are connected by a cheap, hollow door. He's an extremely light sleeper with chronic fatigue syndrome and needs his sleep, and it sounds like almost every sound is coming through this door; the main problem being an alarm clock and my snoring ;). We rent, and I was thinking of getting drywall and putting up drywall (2 panels with Green Glue in the middle) across the entire wall. Is that crazy? Or do you think it would work? Any advice on other solutions? We don't need to use the door and can completely block it off.

If the door is the bulk of the problem, you might try this:

A) caulk the door completely shut with a temporary sealant. I can't think of the names of the top of my head, but some caulks exists and are available at Menards and Home Depot and the like that are MEANT TO not stick. You put them on and when dry the beads can be pulled up. MAKE SURE TO TRY A SMALL INCONSPICUOUS SPOT TO MAKE SURE IT WILL WORK OUT FOR YOU.

B) buy some insulation or smoething and put it in front of the door ina big huge stack or a couple layers stapled to the frame or something. Don't leave it exposed, as you don't want to touch it or breathe it, i suppose, but:

once you do those, you could see if the noise is cut down alot.

You may very well be able to accomplish what you need without bothering with Green Glue at all, and you may not want to modify a rental property for fear of the landlord becoming perturbed. One thing is sure: if it is the door t hat is the problem, fixing the walls won't help you much at all.


If the temporary improvements tot he door work out, the next step would be to add some weight to the sealed door, or find a way to safely temporarily put drywall or MDF + an air space in front of the door to make a semi-permanent cover. use insulation in the air space.

I'd just replace the door with a solid-core model. That sounds like the weak point. Replacing the door can't be more than a couple hundred dollars. Even if the place is a rental if the work is done right, no one would be the wiser. Just get the same door design.

that's a way better idea than my talka bove, if replacing the door isn't too much $$$ or something that will cause you problems with the landlord.

I am renovating an apartment, and currently have walls at stage where there is plaster, with brick behind. Can Green Glue be applied directly to the plaster, with wallboard on other side, or do I need to screw wallboard to the plaster and then apply Green Glue and another sheet of wallboard?

Thanks

no, you can GG right to the plaster.

GGCo has minimal experience with this, but our European customers have reported good success in using that technique to modify some apts/condos. They were able to bring all of the rooms up to whatever spec's exist in the UK. That's all the information i have.

But GG goes betwen stiff things, and plaster is stiff / plasterboard is stiff, so that's ok.

Can Green Glue be applied to a sheet of plasterboard which is then put up onto a plastered wall?
I want to avoid using two sheets of plasterboard.

yeah, see my post right above.

From the Green Glue Company FAQ (http://www.greengluecompany.com/faq.php#A.04):

"4. Can I use Green Glue with only one layer of drywall?
No. Green glue needs to be a constrained layer, meaning that Green Glue is sandwiched between to rigid, dense layers of building material. There is no limit to how many drywall / Green Glue layers you can utilize, and performance will improve as the # of layers goes up. You can save valuable $$$ by using slightly less Green Glue in each damping layer if your walls are to have more than 2 layers of drywall. For floors, you can use any common materials (cement board, OSB, plywood, etc.)"

What that means is just t hat adding GG on the back of a sheet of drywall without anything stiff behind it won't do you any good.

So if you had this wall:

drywall
studs + insulation
drywall

But smeared Green Glue all over the drywall beofre putting it up, the Green Glue wouldn't help you at all.

In the cases mentioned above with plaster surfaces, the plaster surface is stiff/rigid and would just replace one layer of drywall.

all the comments on that use that i have are given above.

Please forgive me if I am asking a stupid question, but wouldn't the green glue be constrained between the wall and the new layer of plasterboard?

ya, that comment was just meant for typical american constructions where people ask if they can smear the glue on the drywall but not constrain the glue with anything else.

What that means is just t hat adding GG on the back of a sheet of drywall without anything stiff behind it won't do you any good.


Hi Brian. Thanks for the followup. I *did* understand that. In fact we're 50% throught GG'ing and screwing the second layer of 1/2" drywall in our theater as of 10 minutes ago. I quoted that FAQ because it explicitly mentioned "rigid, dense layers of building material". I didn't know if a plastered wall would qualify, that's all.

-drin

Thanks for the advice.

I have now used green glue on my wall but in nearly three weeks some thin blobs on the outside of the plasterboard are still not dry: they are tacky to the touch. This must mean that the green glue between the sheets of plasterboard are still wet-so how long does it take to dry?

As far as I know it remains tacky to the touch. That IS dry for GG. The point is that it needs to remain elastic so as to provide damping when sound travels through the top layer of drywall. If the GG was dry it would simply pass the sound through.

-drin

dangit! i wanted to get the 900th post in this thread. lol

no, seriously, drin is right, those blobs won't turn hard/dry, at least in your/my lifetime

I have now used green glue on my wall but in nearly three weeks some thin blobs on the outside of the plasterboard are still not dry: they are tacky to the touch. This must mean that the green glue between the sheets of plasterboard are still wet-so how long does it take to dry?

If you think it stays tacky on the wall, have someone walk through it and step on your carpet! Not good for the WAF at all!

Thanks for the information. For someone who has never used Green Glue before it isn't immediately obvious what is meant by "dry" on the GG company website.

Hey guys,

Just went through the entire thread for the second time. I think its about time to run my plan by the gurus.

accts4mjs was kind enough to give me a detailed description of his results, and now i think i know how much will be 'enough' for my sound proofing needs without going too crazy. Basically more is better (obviously) but with the diminishing returns i dont want to break the bank or lose a ton of space.

Room is in the basement. I have 2 exterior walls, one shared wall, and a crawl space that is 4' cement, and then 4' of open space. The far side of the crawl space is an exterior wall and the side of the crawl space is an interior wall to the laundry room/stairs leading to the main floor.

Heres a diagram to show what im talking about, in case that was confusing.
http://img.photobucket.com/albums/v212/Minhas/House%20Construction/basementrender.jpg

So i'd like to conserve as much space as i possible can since my pool table is already going to be a tight fit.

I was thinking of doing 1/2"-gg-1/2" drywalling for the 2 exterior walls and the crawl space wall on standard 2x4 studs. Then, for the shared wall i'd do staggered studs on a 2x5 plate with 1/2"-gg-1/2" on both sides of the wall.
Ceiling would be a GG sandwich with no decoupling (dont want to spend the money on RSIC and im not overly concerned with bass transferring upstairs.)
Im having a tough time deciding whether staggering that one shared wall is useless or not, since if i dont decouple the ceiling, i believe there will be an easy flanking path for sound to travel to the other side of the basement. Am I correct in thinking this?

OK on to the next problem. Im planning on mounting the TV into the crawl space wall....so i'd be cutting a chunk of the concrete and mounting the tv so its flush to the wall. This will obviously give me a huge hole that i'd need to fix. What would be the best way to solve this?

My thoughts:

I think that if your willing to spend the money on greeg glue and extra drywall, you should go ahead and spend it on RSIC clips as well. It’s probably somewhere in this tread, but decoupling the ceiling may be more effetive than the GG sandwich if you are just going to do one. By my rough calcualtion, you would need 56 clips for the ceiling. Inlcuding the hat track it should run ~$300.

For the TV, I think the best solution would be to build a GG box behind the TV (2 layers of plywood would probably be easiest), cauled to the drywall. This would make it so the TV is still essentially in the room, just that the room is deeper at one point.

My thoughts:

I think that if your willing to spend the money on greeg glue and extra drywall, you should go ahead and spend it on RSIC clips as well. It’s probably somewhere in this tread, but decoupling the ceiling may be more effetive than the GG sandwich if you are just going to do one. By my rough calcualtion, you would need 56 clips for the ceiling. Inlcuding the hat track it should run ~$300.

For the TV, I think the best solution would be to build a GG box behind the TV (2 layers of plywood would probably be easiest), cauled to the drywall. This would make it so the TV is still essentially in the room, just that the room is deeper at one point.

really only 56? i used the pac calculator and got something like 90-110 clips...that would be about 600 bucks just on clips. Also, how much ceiling height would i be losing using these clips? at 8', i dont want to be dropping the ceiling down any more than i absolutely have to.
Thanks for the quick reply!

Edit: and you read my mind on the tv, i was just thinking that!

Using the recommended 48" spacing, a 30' long room would need 8 clips per row (I'm assuming teh joists run paralell to the TV wall - this could be wrong). For the 14' room width, you would need 7 rows (8 woudl be recommended, but I think 7 would be plenty). So 7 rows x 8 clips per row = 56 clips.

I forget the amount fo ceiling height you lose - it is one the PAC site somewhere. I think it's something like 1 5/8" plus the thickness of the drywall.

Edit: Yep, it's 1 5/8" plus drywall.

thank you for taking the time to help me with that. I really havent done too much research into RSIC and the pac website isnt as noob friendly as the green glue one :)

my width is actually 16 at the widest point, so if im getting this right, at 24" spacing i will need 8 rows x 8 clips, so i'd do fine with 64. Still much lower than the excel calculator pac has. THis pleases me. Just unsure if i'd be willing to lose 1 5/8" plus 2 layers of drywall....thats almost 3" of headroom and would put the pool table area at 7' ceilings. Im going to have to think long and hard about it.

Thanks again for your help!

I haven't been in this thread for a LONG time, but i'll definitely put in a chip for the RSIC clips - I did them with GG and my HT is amazingly well insulated for low frequency sound.

cheers.

PAP--how did you find intallation of two layers of drywall onto the hat channel? Difficult?

I haven't been in this thread for a LONG time, but i'll definitely put in a chip for the RSIC clips - I did them with GG and my HT is amazingly well insulated for low frequency sound.

cheers.Doesn't the data on the GG website show a improvement above 200Hz by using GG + RC vs. just GG and a decrease in low frequency performance (below 200Hz)?

GG (http://www.greengluecompany.com/images/transmissionLossTests/OL05-1011_Report.pdf) vs. GG + RC (http://www.greengluecompany.com/images/transmissionLossTests/OL05-0825_Report.pdf)

Wouldn't that make GG + RC less desirable for isolating low frequency sound?

My question is why does 1/2" | GG | 1/2" | STUD | 5/8" | GG | 5/8" work better than 5/8" | GG | 5/8" | STUD | 5/8" | GG | 5/8" ?

wall with 1/2" & 5/8" (http://www.greengluecompany.com/images/transmissionLossTests/OL05-1035_Report.pdf) vs. wall with only 5/8" (http://www.greengluecompany.com/images/transmissionLossTests/OL05-1049_Report.pdf)

So, would 1/2" | GG | 1/2" | STUD | 1/2" | GG | 1/2" work even better or am I reading too much into the reports?

Wouldn't that make GG + RC less desirable for isolating low frequency sound?

RC= Resilient Channel
RSIC = Resilient Sound Isolation Clip - http://www.pac-intl.com/rsic.htm

Not the same thing.

RC= Resilient Channel
RSIC = Resilient Sound Isolation Clip - http://www.pac-intl.com/rsic.htm

Not the same thing.Yes, I'm aware of that. However the RSIC holds DWFC which the drywall is then attached to. Which isn't that different from RC. I have seen very little information showing how RSIC + DWFC affects low frequencies. This (http://www.pac-intl.com/pdf_test/test_RAL_AFDTL.pdf) seems to show the RSIC + DWFC has a minimal effect by itself on low frequencies. The additional mass of the drywall seems to make the difference, not the RSIC + DWFC itself.

Without the folks at GG adding a RSIC + DWFC test to their collection of results, the impact of using all these things together is somewhat unknown

I've been out of this thread for a long time too, but I'm not seeing in the last page or so of anyone using RSIC AND RC. I'm willing to admit that just because I'VE never seen it, doesn't mean it isn't done. Now, I've seen RSIC holding DWFC (drywall furring channel), which, again, is completely different than RC. I also don't see a mention of it in the doc linked above by "this."

Just trying to understand the RSIC + RC thing.

Tom

I've been out of this thread for a long time too, but I'm not seeing in the last page or so of anyone using RSIC AND RC. I'm willing to admit that just because I'VE never seen it, doesn't mean it isn't done. Now, I've seen RSIC holding DWFC (drywall furring channel), which, again, is completely different than RC. I also don't see a mention of it in the doc linked above by "this."

Just trying to understand the RSIC + RC thing.

TomIsn't a drywall furring channel/ hat track basically the same thing as RC? :confused:

Either way, RSIC + DWFC (which is what I meant above) gives similar results to RC, and there's no data available how GG much it will help RSIC + DWFC. Just like there's no data to show how much GG helps a staggered stud wall or double stud wall.

Without the folks at GG adding a RSIC + RC test to their collection of results, the impact of using all these things together is somewhat unknown.

Not test results, but look at this link, starting about halfway down where the heading starts "Table – choosing the right decoupling system for low frequency performance."

Best I can do - send Brian or Ted a PM, I am sure they can expand on it further.

Isn't a drywall furring channel/ hat track basically the same thing as RC?
.

Similar but different. RC comes in two flavors, RC1 and RC2. RC1 only has one leg and holds the drywall 1/2 inch off the wall. RC2 has two legs but the legs are often an open mesh affair to provide a little more spring. I used RC2 in my ceiling only because of the size of the room and I didn't want to go for RSIC clips. It was also pre-GG era.

I used to have a left over piece but can't find, I also can't find a link but I'll look some more.

Found one, terrible picture a stack of RC1 on left one piece of RC2 on right look for the holes in the legs hard to see they are almost perpendicular to the camera.

http://www.extremesoundproofing.com/Products/Resilient_channel_is_one_of_th/resilient_channel_is_one_of_th.htm

Not test results, but look at this link, starting about halfway down where the heading starts "Table – choosing the right decoupling system for low frequency performance."

Best I can do - send Brian or Ted a PM, I am sure they can expand on it further.I assume you meant to post this URL (http://www.greengluecompany.com/understandingHowDecouplingWorks.php)? ;)

I assume you meant to post this URL (http://www.greengluecompany.com/understandingHowDecouplingWorks.php)? ;)


Right you are. . . Sorry about that.

Just like there's no data to show how much GG helps a staggered stud wall or double stud wall.

I would have sworn I saw such data at one time, but I do not see it on the GG web page.

I would have sworn I saw such data at one time, but I do not see it on the GG web page.It always makes things harder to decide not having all the information. We know that Green Glue adds 11dB to the STC of a standard insulated double 5/8" drywall 2x4 wood stud wall. From 44dB to 55dB... We also know that a standard insulated staggered stud double 5/8"drywall wall has a STC of 54dB. However, I know that we can't assume an 11dB improvement to a STC of 65dB for an insulated wall using staggered stud construction and drywall GG sandwich on both sides.

For example, GG only adds very little to an insulated wall using RC and double drywall. Or you can look at it differently and say that RC adds virtually nothing to an insulated wall using a drywall GG drywall sandwich on both sides.

I guess my point is I don't want to build a staggered stud wall if it has very little improvement over the standard wall (if a drywall GG sandwitch is used on both).

I apologize if this was covered earlier (I only read through the first 20+ pages), but it should be a semi simple yes or no answer...

From a drop ceiling standpoint has anyone tried green gluing 2 ceiling tiles together back to back, and seeing if there was a noticeable improvement in isolation? Obviously this would be a less than ideal situation, but there are times when a drywall ceiling just isn't feasible. I'm not even sure if what I'm suggesting makes real sense, but if you beefed up your ceiling grid to support the extra weight (double the tiles + weight of glue), it makes sense to me that it might help.

I apologize if this was covered earlier (I only read through the first 20+ pages), but it should be a semi simple yes or no answer...

From a drop ceiling standpoint has anyone tried green gluing 2 ceiling tiles together back to back, and seeing if there was a noticeable improvement in isolation? Obviously this would be a less than ideal situation, but there are times when a drywall ceiling just isn't feasible. I'm not even sure if what I'm suggesting makes real sense, but if you beefed up your ceiling grid to support the extra weight (double the tiles + weight of glue), it makes sense to me that it might help.I'm no expert, but I would expect the answer is no. You just don't have an airtight seal between the tiles and the metal frame.

[quote]We know that Green Glue adds 11dB to the STC [\quote]
Yeah, but .... STC doesn't count in our application. Green Glue's real benefit begins to pipe in below 250 Hz which is why they provide both the STC (an industry thing) and the TL numbers down to the flanking limits of the lab.

No...gluing two ceiling tiles together will only lighten the load in your wallet. On the other hand, cutting two layers of drywall (with green glue between the layers) and using that instead of the lightweight ceiling tiles would make a big difference.

[quote]We know that Green Glue adds 11dB to the STC [\quote]
No...gluing two ceiling tiles together will only lighten the load in your wallet. On the other hand, cutting two layers of drywall (with green glue between the layers) and using that instead of the lightweight ceiling tiles would make a big difference.
is it the stiffness and/or density or the drywall that is required with the green glue? how much improvement would you expect, given that the drywall wouldnt be sealed to the ceiling grid (or is it too hard to say as its quite an odd situations)?

It is the mass that makes it work and reduces the rattles from the ceiling grid.

thanks Dennis

Ok, so I now read all the way through this thread. It took me many hours, but it was time definitely well spent. After reading Brian's Posts like this one (http://www.avsforum.com/avs-vb/showthread.php?p=6265797&&#post6265797) and many others I'm still not sure how something like 3 layers of 3/8" drywall with 50% GG between them or 3 layers of 3/8" drywall with 100% GG between them would compare to 5/8" drywall + 1/2" drywall with 100% GG.

Per Brian's 5 principles:

1) Mass: Same.

2) Decoupling: I would expect it to be the same.

3) Absorption: ?

4) Resonance: ?

5) Conduction: ?

I would think having two layers of GG in the stack-up would yield better performance even though the mass is the same, but I have no idea by how much, or if it would be worth the extra cost to do the 3 layers of 3/8" over 5/8" + 1/2".

Anyone have any educated opinions about this?

Dried Green Glue on your carpet : here's something that worked for me : sprinkle detergent powder ( I use supermarked own brand ) on the area. Clean with steam cleaner.
I don't know where it goes-presumably to the bottom of the carpet. Or am I doing a scary thing with Green Glue?

there's a 3 yr old living above me in a late '50s apt building in NYC. need to do something to minimize the sound transmission from the kid's footsteps as he continually runs everywhere. main room is about 500 sq feet. i don't want to remove the existing ceiling so i'm contemplating putting up another layer of 5\8 sheetrock with green glue or just using quietrock. my questions are 1) will either of these help reduce the noise i'm hearing daily to a level that'll be tolerable, 2) if so, which method is preferred, and 3) do i need to have an electrician reinstall the elec boxes for the hanging lights afterward?

Ok, my problem is my computers subwoofer in the upstairs room (that will soon my my HT room,) shakes my bedroom downstairs on the far opposite side of the house. It seems most people are lucky enough to put a HT in a basement, which would really help. I am hoping to put in a much larger subwoofer than my computer has (well it is THX.) It seems I should concentrate on the floor. Even that GG page combines Ceiling/Floor and really only talks about the ceiling. I am really hoping I don't have to do staggered floor joists.
Anyone have a success story on this situation to share?
Thanks, Warren.

Hi everyone! New to ..uh, everything, so here goes with my situation: I have a 50y/o townhome with concrete party walls. The difficult part is that the door frame is pretty much butted right up to the concrete wall, which leaves me little room to add mass to the wall without having a funky cutout for the door. There is currently some paneling and trim i have to take down. Anyways, I was considering either mlv, but i would have to cover it up with paneling or drywall anyway, or the greenglue/drywall. Is it possible to adhere the drywall directly to the existing concrete wall? Not with green glue, of course..and right now im only assuming that the wall is level enough to do this.
Any ideas?

I don't know if this is the right thread to ask this, but here goes:

I'm going for a "room in room" construction and today my ceiling is open in the sense that the beams are visible. I'll "interlace" the beams for the ceiling and floor like in the attached picture. I'll probably put 2 layers of drywall with GG between in the ceiling.

Now, my question is this: Will there be at all a noticeable effect by adding some layers of drywall between the current beams as sketched on the image below (with or without GG)? Or would a third layer of drywall do just as well?

I'm mainly concerned about the lower frquencies (sub 80Hz).

Insulation and a 2nd layer of something on top of the floor would probably be more beneficial.

Insulation and a 2nd layer of something on top of the floor would probably be more beneficial.

Oh, yes, I'll have insulation. Just forgot to draw it :o

The thing is that the room above is finished and there'sno way my wife will let med turn that room upside down to add a new layer of "something" on the floor. Besides there are are a few layers already:

From the beams and up:
- 25mm particle board
- 4 mm "footstep noice reducer thingie" (sorry, don't know the English term)
- 4 mm "footstep noice reducer thingie"
- 13 mm particle board
- "parquet underlay"
- parquet

So I have kind of prepared (a little) for having a HT below already, so I'm looking for the best way to sound insulate from the below now.

Okay, while looking to build a portable vocal booth I got a good deal on soundboard ($3 per 4'x8' sheet).

Now, I've carefully read a lot of Brian's comments concerning soundboard here, his recommendations of drywall, and the recommendations/info on the main site.

However, because I want portability and ease of storage when it's not in use, I can't go with many layers or the weight of drywall. I'm trying to get the best possible noise reduction while keeping my makeshift walls less than say, 1 1/2 inch thick, and while keeping the weight as low as possible.

Which sandwich would give me the best possible results with these constraints?

plywood-gg-soundboard?
soundboard-gg-soundboard?
soundboard-roofing felt-soundboard?
plywood-roofing felt-soundboard?
some other lightweight combination with soundboard?

Your requirements are at odds with each other - your application is a good use of the STC ratings. But the curve underlying STC will more or less follow mass law - which says for sound isolation - the more mass the better.

The GreenGlue site has numerous comparisons to other material constructions - so you can compare and see which has best STC vs. least mass.

Looking at the Green Glue calculator I started wondering: How much difference is there between the "Best" (3 tubes/sheet) and "Normal" (2 tubes/sheet) applications?

If I have enough Green Glue to do my walls with the "Normal" amount, would I be better off doing all the walls this way, or would I see some improvement doing critical walls with more (let's say 3 tubes/sheet) and the rest with less (1 tube/sheet)?

Here's a picture of my basement layout.
http://people.uleth.ca/~courtney.atkinson/images/pictures/Basement_apartment_prep_for_HT.jpg

The left and right walls are stepped concrete. They're the full height of the basement at the top of the picture, and not there at all at the bottom of the picture.

As the concrete steps down, there are 2X6 studs that hold the rest of the house up, and below them, and in front of the concrete, 2X4s to simply hold the insulation and vapour barrier in front of the concrete. This left a ledge about 7" along the side of the foundation that follows the steps in the concrete.

Rather than leave these steps, I've gone ahead and framed the wall up flush to the ceiling. This will act as very wide staggered stud wall. I've screwed all the walls directly to the joists in an attempt to save costs.

My goals are to:

Keep voice travel to a minimum both up and down
Keep the sounds of foot traffic to a minimum. I have cork floors above this area and although it's not as loud as hardwood, I don't want to hear steps loudly coming from the main floor.
Keep the noise of the wind, that comes from the sides, to a minimum


Here's my plan, and I'm seeking feedback on it's viability:

Assuming I've looked after the little (read big loss areas) like outlets, pot lights, and doors
I'm planning on going DD (5/8"), plus medium coverage GG, (plus insulation where it doesn't already exist) on the walls
I'm planning on using either RSIC-1 or Isomax clips, plus DD (5/8"), plus GG, plus insulation in the ceiling


Would you folks mind letting me know what you think about this plan and how it will work?

...
My goals are to:

Keep voice travel to a minimum both up and down
Keep the sounds of foot traffic to a minimum. I have cork floors above this area and although it's not as loud as hardwood, I don't want to hear steps loudly coming from the main floor.
Keep the noise of the wind, that comes from the sides, to a minimum


Here's my plan, and I'm seeking feedback on it's viability:

Assuming I've looked after the little (read big loss areas) like outlets, pot lights, and doors
I'm planning on going DD (5/8"), plus medium coverage GG, (plus insulation where it doesn't already exist) on the walls
I'm planning on using either RSIC-1 or Isomax clips, plus DD (5/8"), plus GG, plus insulation in the ceiling


Would you folks mind letting me know what you think about this plan and how it will work?
I did sound isolation for my entire basement using RSIC, DD (5/8") and GG. I am very pleased with the results! One thing I did differently than what you described was I did not directly attach my walls to the floor joists. I decoupled them using RSIC clips. I don't know how big of a difference that will make.
The other thing that needs to be considered that you did not mention is your HVAC system. This can be a critical weak-link. I used a separate zone for my basement that is separated from the main zone by using an isolating manifold. Sound can easily travel through regular duct-work so be sure you have a plan for dealing with this area.

Looking at the Green Glue calculator I started wondering: How much difference is there between the "Best" (3 tubes/sheet) and "Normal" (2 tubes/sheet) applications?

If I have enough Green Glue to do my walls with the "Normal" amount, would I be better off doing all the walls this way, or would I see some improvement doing critical walls with more (let's say 3 tubes/sheet) and the rest with less (1 tube/sheet)?

Anybody?

I've read so many of these GG posts that my eyes are starting to bleed. I believe the recommendation is to use 2 tubes per sheet (normal) on all the walls/ceiling, etc. Otherwise, your walls where you used 1 tube will be your weakest link.

I'm still trying to talk myself into buying 6 cases of GG.... ouch. It's either buy the GG or just use DD. I've read all the data and opinions, but it's a big nut to crack and I could use the money else where.

Best of luck.

I've read so many of these GG posts that my eyes are starting to bleed. I believe the recommendation is to use 2 tubes per sheet (normal) on all the walls/ceiling, etc. Otherwise, your walls where you used 1 tube will be your weakest link.

I'm still trying to talk myself into buying 6 cases of GG.... ouch. It's either buy the GG or just use DD. I've read all the data and opinions, but it's a big nut to crack and I could use the money else where.

Best of luck.

I made the choice just yesterday to scrap GG and just go with the double drywall (my framing is all isolated from the main house)...

Isolation was important, proper in-room treatments were more important, as was a better screen, better chairs, better speakers, and on and on.

BTW - one tube per sheet will yield 70% of the optimal (2-3 tubes per sheet).

I decided on using green glue (even though it's not available in my country, and that made it a bit more expensive) simply because of the following:
- price may be high, but compared to the total cost of the HT build it is insignificant
- it's not something I can do later if I find DD insufficient. It's now or never.

So for peace of mind, knowing I've done the best I could for sound isolation, it's not a huge price to pay.

Been reading this thread and my head hurts?
I have a new construction daylight basement garage room aprox 16 x20 with 9' ceilings. two walls are concrete with 2x4 stud and 5/8 dw. Other wall seperates the basement with a furnace-utility room. Back wall facing the garage is not built. All three wall currently built have insulation but are attached to the silent floor joists. the ceiling is also insulated with 5/8 dw.
SOOOOOOO!
Real world experiance should I tear out all the drywall. isolate the non load bearing walls . RC1 with hat channel, 5/8 gg 5/8.
OOOOR?
simply add GG and another layer of 5/8 all around? could still isolate the wall to be built. It just faces the cars and the garage door.
OOOOOOr add two more layers (that would be three total) of 5/8 with GG between on layer.??
I dont want to tear out the sheet rock if the differance is something non tech guy would notice??
Thanks for any imput

I just put up an additional layer of 1/2" drywall with 2 tubes of GG between on a common wall between two condo's. It has only been completed a day but I notice no difference. How long does GG take to dry. I know it says 30 days on the container but I am under the impression I should notice at least some reduction of sound.

From everyone's experience, can you tell me your experiences on this curing time for GG.

Thanks,

Mike

The product is worth it even for room within room type of construction.

We've not only used the product; but, have a pretty interesting demo in the store.

We have a transducer ... one of those items designed to be attached to a wall or ceiling to create a PA or background music source. We place the transducer on our 4' x 22' x 3cm marble counter top. We get music (rather loud at that). We then place two pieces of 5/8" stacked drywall on the counter and the transducer on the stack. Still get loud music. We then lay two 5/8" pieces on the counter (laminated with green glue between them). No sound. No music. Technically, this is impact noise, but the demonstration effectively illustrates dampening.

Hi Dennis. I'm really interested in GG as well. However, I conducted test 2 days ago. I cut 2 pieces of 5"x5" drywall. Then in between is a 1/4" soft styrofoam. I was just holding the 3 piece together and sticked it in my ears. I tapped the other side and could hardly hear the sound transmission. Now I screwed the two 5"x5" drywalls with styrofoam in between, sound is easily transfered. :(

I remember someone told me that the second drywall still needs to be screwed. My guess is, sound will be transfered via the screws. Am I correct that sound will still be transferred?

Repost---Green glue starting to scare me. Its a lot of money. with out room isolation is it going to help?? enough to offset the expense? 1200.00 for my room.
Been reading this GG thread and my head hurts?
I have a new construction daylight basement garage room aprox 16 x20 with 9' ceilings. two walls are concrete with 2x4 stud and 5/8 dw. Other wall seperates the basement with a furnace-utility room. Back wall facing the garage is not built. All three wall currently built have insulation but are attached to the silent floor joists. the ceiling is also insulated with 5/8 dw.
SOOOOOOO!
Real world experiance should I tear out all the drywall. isolate the non load bearing walls . RC1 with hat channel, 5/8 gg 5/8.
OOOOR?
simply add GG and another layer of 5/8 all around? could still isolate the wall to be built. It just faces the cars and the garage door.
OOOOOOR add two more layers (that would be three total) of 5/8 with GG between one layer.??
I dont want to tear out the sheet rock if the differance is something non tech guy would notice?? bang for the buck and extra work.
Thanks for any imput

Here is info that I received whenever I asked similar questions:

Decoupling:

The resilient clips, double walls or staggered walls are all examples of de-coupling. De-coupling reduces the direct vibration through a common structure like a stud. Very important element.

Absorption:
Next element is absorption... simple fiberglass insulation. Absorbtion reduces the resonance that can build within a hollow air cavity.

Mass:
Very important element. This is what Mass Loaded Vinyl (MLV) brings to the party. Double drywall, however, is the lowest cost mass available. Best to use double 5/8". A large mass is more difficult for a sound wave to move than a small mass.

Damping:
The last element is damping. This is what Green Glue, Quiet Glue and Quiet Rock incorporate. Damping reduces the vibration within a panel. This leaves less vibration available to travel through the studs, the clips, and the air cavity between the studs.

All these elements perform different and distinct functions, so you see that de-coupling clips don't replace damping Green Glue. Seal up cracks with drywall compound or caulk.

Guys,
Stupid question time.

If putting Green Glue between layers of drywall, Do I still use drywall screws on both layers of drywall?

I dont know if that would be desireable because it may cancel the absorbant qualities of the wall if it cannot flex to cancel out sound transmission but I am not sure that the drywall will stick without screws by only using this "Glue".

My assumption would be- Drywall screws on both layers with GG in between.

"I'm frickin Dyin ova heer" :cool:

Since your walls are already built making RSIC clips an expensive proposition, I would recommend you use 2 or 3 layers of 5/8" drywall with green glue.

Green glue takes sometime to "setup" and as we've been told before, the sound damping may seem worse when it is first applied because the moisture that hasn't evaporated yet causes more sound to be transferred (at first only) than not using GG at all.

I decided to use it... I've got 5 cases in the basement waiting to be applied.

Thanks for the reply.
I believe I'm going to follow your suggestion by adding one to two more layers of 5/8 over the top of my current walls with GG.
I will pay very close attention to all air leaks. Will also put any lights in the soffit to keep a good seal on the ceiling.
Any advise on where to get GG at the best price?

So damping simply reduces the amount of sound that "will" be traveling thru my standard framed walls. Correct?

Here is info that I received whenever I asked similar questions:

Decoupling:

The resilient clips, double walls or staggered walls are all examples of de-coupling. De-coupling reduces the direct vibration through a common structure like a stud. Very important element.

Absorption:
Next element is absorption... simple fiberglass insulation. Absorbtion reduces the resonance that can build within a hollow air cavity.

Mass:
Very important element. This is what Mass Loaded Vinyl (MLV) brings to the party. Double drywall, however, is the lowest cost mass available. Best to use double 5/8". A large mass is more difficult for a sound wave to move than a small mass.

Damping:
The last element is damping. This is what Green Glue, Quiet Glue and Quiet Rock incorporate. Damping reduces the vibration within a panel. This leaves less vibration available to travel through the studs, the clips, and the air cavity between the studs.

All these elements perform different and distinct functions, so you see that de-coupling clips don't replace damping Green Glue. Seal up cracks with drywall compound or caulk.

Awesome posts! A lot of things got cleared up in my head. :)

Thanks. ;)

yes but are drywall screws supposed to be used in conjunction with Green Glue?

yes but are drywall screws supposed to be used in conjunction with Green Glue?
Unforunately, screws can be a transport to sound. GreenGlue isn't an adhesive as well. I've asked this question before and yes you do need to screw the second drywall.

Repost---Green glue starting to scare me. Its a lot of money. with out room isolation is it going to help?? enough to offset the expense? 1200.00 for my room.
Been reading this GG thread and my head hurts?
I have a new construction daylight basement garage room aprox 16 x20 with 9' ceilings. two walls are concrete with 2x4 stud and 5/8 dw. Other wall seperates the basement with a furnace-utility room. Back wall facing the garage is not built. All three wall currently built have insulation but are attached to the silent floor joists. the ceiling is also insulated with 5/8 dw.
SOOOOOOO!
Real world experiance should I tear out all the drywall. isolate the non load bearing walls . RC1 with hat channel, 5/8 gg 5/8.
OOOOR?
simply add GG and another layer of 5/8 all around? could still isolate the wall to be built. It just faces the cars and the garage door.
OOOOOOR add two more layers (that would be three total) of 5/8 with GG between one layer.??
I dont want to tear out the sheet rock if the differance is something non tech guy would notice?? bang for the buck and extra work.
Thanks for any imput

I've been researching GreenGlue and one comment I found from a tester said that GreenGlue was the equivalent of adding another layer of drywall. So, it might be much cheaper for you to skip the greenglue and add another layer of drywall, if you have room for the extra width.

I wouldn't trust the testing results from those Orfield lab tests from 2005, as touted by GreenGlue. I reviewed the tests and they are highly suspect. I'm very surprised that a certified lab would agree to those lax protocols. Does anyone know of any other lab tests? I searched and can't find any.

Easy,

Why don't you contact the lab and express what is so lax? Maybe they can help you. All contact info is on every test. And they are among only a few labs that are NVLAP certified. Labs don't agree to client protocols, they define the protocols. Otherwise where's the objective analysis?

Adding Green Glue isn't at all the same as adding more drywall. Great question, though and covered at length here: http://www.greengluecompany.com/greenGlue-vs-ExtraDrywall.php

Plenty of lab tests here: http://www.greengluecompany.com/transmissionLossTests.php

Quiet Glue is far cheaper than Green Glue from everything I can find online as of today ($139.95 per case of 12/29oz tubes) ... is there still an AVS member discount for GG?

I'm going to need 15 cases, or 8 five gallon buckets...

This has been discussed before, but it really boils down to how well each product functions, right? These are not the same materials. On a per ounce basis, the results are interestingly dissimilar.

http://www.greengluecompany.com/greenGlue-vs-EngineeredDampingGlue.php

Hi Ted.
Sorry, haven't been up to date with the forum for a year or so...

We corresponded regarding Green Glue applications on SIPS panels, and you said at the time that you'd be conducting some tests in the future... any word?

My two easiest interior treatment options will cost about the same for materials: SIP/GG/drywall/GG/drywall, versus SIP/RSIC/drywall/GG/drywall. (5/8" drywall).

I'd like an idea of which one will be more effective, since the SIPS panels themselves are a terrible STC of 22.

I am just wondering if you guys are building your theaters so cheap that $1000 is blowing the budget? If you look at your total budget maybe you will consider it a fairly good investment. If you buy too cheap of a projector and aren't happy with it, it is easy enough to replace later, but the walls.....
Warren.

Tgorle, how have you been?? I would suggest that you introduce some flex in the system. 24" stud spacing works better than 16" due to more flex / less contact. While the small air cavity created by the clips isn't necessarily a good thing, the decoupling and introduced flex will help.

Ideally you would decouple from the SIP with another stud wall (larger air cavity). You'll want some little bit of insulation in whatever airspace you create.

Thanks Ted.

Easy,

Why don't you contact the lab and express what is so lax? Maybe they can help you. All contact info is on every test. And they are among only a few labs that are NVLAP certified. Labs don't agree to client protocols, they define the protocols. Otherwise where's the objective analysis?

Adding Green Glue isn't at all the same as adding more drywall. Great question, though and covered at length here: http://www.greengluecompany.com/greenGlue-vs-ExtraDrywall.php

Plenty of lab tests here: http://www.greengluecompany.com/transmissionLossTests.php

Went to your link. I see that all the tests were done by the same lab, whose protocols can certainly not be deemed as total independent testing. Are there any lab tests that were done by someone other than Orfield?

I am just wondering if you guys are building your theaters so cheap that $1000 is blowing the budget? If you look at your total budget maybe you will consider it a fairly good investment. If you buy too cheap of a projector and aren't happy with it, it is easy enough to replace later, but the walls.....
Warren.

Personally, I think $1,000 is quite a bit of money for glue. And the person posting above needs 15 cases, or around $2,600 for glue. That doesn't include the two layers of drywall and installation costs. I think anyone would be hesitant at these prices.

How do you get 15 cases? Two 9x16 walls, two 9x20 walls and a 16x20 ceiling is about 5 cases @ 2 tubes per sheet. Many choose 1 tube per sheet given it is ~75% effective.

Having been around this forum for 5 years, do you really thing Green Glue is glue?

" the tests were done by the same lab, whose protocols can certainly not be deemed as total independent testing."

Sounds like you have an issue with ASTM, the group that writes the specific protocols for the lab tests. Perhaps you should contact them also.

Having been around this forum for 5 years, do you really thing Green Glue is glue?

Cause everyone knows Ted is sitting there with a vat of elmers glue and easter egg green dye having an evil laff at pulling the wool over AVSers eyes including acoustic engineers...

People pay for it because it has the best isolation for bang for the buck without exotic construction techniques. Maybe they should have called it Emerald Viscoelastic Damping Compound to be more accurate - but anyone that uses it refers to it as that green gunk...

I have closed the curtains now...

Sounds like you have an issue with ASTM, the group that writes the specific protocols for the lab tests. Perhaps you should contact them also.

You keep ignoring my question so I’ll ask again. Are there any independent lab tests on GreenGlue besides the Orfield lab tests? For a supposedly certified lab there are some glaring lack of testing controls. I would think that ASTM and NVLAP test protocol methods only detail and test what is brought to them by the client, which unfortunately leaves way too much possibility for underhandedness and trickery before the test materials reach the lab for testing. Here's my problems..

1. They allowed GG people to assemble and bring in THEIR OWN drywall already glued and attached together.

From the report..

""The gypsum board panels were laminated together with green glue. The client reported that the green glue was applied from adhesive cartridges in 3/16" beads in a random pattern over the whole panel. The aging period was over 40 days, greater than the 14 days period stated in ASTM Standard E90 for waterbase adhesives. The assemblies were dried on 4' x 8' wood-stud frames, spaced out and with forced air ventilation according to the client""

The lab should have done this work themselves and not trusted GG people to do it. That's like the fox designing the hen house. Glaring error. ..continuing..

""The specimen arrived at the laboratory still mounted on the wood stud frames. Fastener heads on the base layer panel were accessible via pre-drilled holes through the face layer, approximately 1/2" in diameter. A new wood-stud frame was erected in the specimen opening. The glued wall panels were demounted from the drying frames, and then remounted on the frame in the opening.""

""Representatives of the client constructed and installed the specimen wall assembly. A qualified representative of Orfield Laboratories observed the installation and visually inspected the specimen.""

The testing lab should have never let the GG people anywhere near any drywall and the lab should have assembled the wall themselves with GreenGlue bought anonymously along with standard drywall bought in any local store. This is how Consumer Reports does their testing. There is just way too much possibility for hanky-panky if the manufacturer themselves is anyway involved in the testing. This is NOT an true independent test.

2. The test of the unnamed competitor's damped panels was also not to be trusted. From the report..

"Representatives of the client constructed and installed the specimen wall assembly. A qualified representative of Orfield Laboratories observed the installation and visually inspected the specimen.""

Again, never let the manufacturer anywhere near the test, and ESPECIALLY never let them handle a competitors product. Glaring error by the lab.

Finally, there is this...

"The prefabricated damped panels were obtained from another manufacturer and installed as they were received. Seams were sealed with caulk. The perimeter of each face was sealed with 7/8” wide strips of rope-caulk.""

So they let the GG people install the competitiors product while the testing lab only "observed"? I'm sorry, but this lab is using pathetic source controls in their tests and these two tests should be considered invalid because there are just too many possibilities that the test has been compromised in some way. Green Glue could indeed be a very effective product and better than alternate sound isolation methods, but you sure can't objectively tell by these tests. GreenGlue people were incorporated into and hand an big influence on the test itself, which is a big no-no in proper testing protocol.

Cause everyone knows Ted is sitting there with a vat of elmers glue and easter egg green dye having an evil laff at pulling the wool over AVSers eyes including acoustic engineers...

Actually, we don't factually know if GreenGlue is any better than Elmer's glue. I don't see any comparison tests (with proper testing protocols, of course). Right now it's a leap of faith . Costwise, I see Elmer's Glue is less than $14 a gallon at Staples website.

And if Elmers at Staples worked as well - this forum would be full of people using it. They are after all about bang for the buck. Since you have convinced yourself GreenGlue's testing is a sham - your best option is to dye the Elmers Green yourself and convince yourself you banged your buck as hard as you could.

You keep ignoring my question so I’ll ask again.

I am not with Green Glue Company, so you should ask them.

I'm just curious, do you have any experience in lab protocols? You comment on what labs do and don't do. Please don't take that as argumentative, I'm really just curious.

When did you leave?

Last year.

Great product, great people. Some of the smartest people I know work there, actually.

And if Elmers at Staples worked as well - this forum would be full of people using it. They are after all about bang for the buck. Since you have convinced yourself GreenGlue's testing is a sham - your best option is to dye the Elmers Green yourself and convince yourself you banged your buck as hard as you could.

Your logic is flawed. Just because it is popular doesn't mean it is a good deal and a effective product. The dotcom stock market mania of 1999-2000 showed that crowds can be very wrong. Green Glue could be an effective product, but we simply don't know for sure because there are no true independent tests. Is is better than Elmer's glue? Is it better than adding a 3rd layer of drywall? We simply don't know for sure because in the tests we have seen, the sourcing of the material used in the tests is not independent at all and leaves much room for the tests to be compromised. Since a great deal of revenues are at stake, anything is possible.

I am not with Green Glue Company, so you should ask them.

I'm just curious, do you have any experience in lab protocols? You comment on what labs do and don't do. Please don't take that as argumentative, I'm really just curious.

Don't start shooting the messenger. You're evading the subject at hand. After some years, I surely can't be the first person on these boards to bring up these glaring testing deficiences. Consumer Reports and other testing outfits would probably laugh at these testing protocols. When they test a car, they buy it anonymously at a local dealer, they most assuredly do not ask the car manufacturer to send them a car to test. I am reminded of the old infamous radar detector test for a auto magazine. They asked the Fuzzbuster (remember that?) people to send them a detector to test, and it was a ringer. They took it apart and that sample was nowhere near the regular retail model.

Yesterday I called DL Labs, who did the Greenglue moisture test. I spoke to the VP in charge of testing, Mr. Sliva. He signed the test report. BTW, DL labs also permitted Greenglue to provide their own samples for testing instead of sourcing them independently. Mr. Sliva said that there were not any ASTM or NVLAP protocols in existence to restrict the client from submitting their own samples for testing. That is a stunning revelation. There really is a lot of blind faith and wholesale trust when it comes to honesty in sourcing of testing materials these days.

easy, there isn't any impropriety in testing. You may not personally agree or have personally experienced how lab testing is conducted but that really shouldn't justify a comprehensive dismissal of standard accepted independent lab procedures that all competent labs follow.

The protocols you don't agree with (and that is certainly your right) are closely followed at Orfield Laboratories, Riverbank Labs, the famous NRC labs in Canada, WEAL, Owens Corning, National, and most others. This is true whether they are NLAP certified or not. So no, labs are not laughing at one another. They follow ANSI and ASTM standardized testing protocols as a minimum standard.

You might additionally find it interesting to know that UL labs (both acoustic and fire testing) operate this way as well.

If I could observe, I think maybe you presume too much ability to fudge test results. If you were to witness a few of these tests I really feel you'd conclude there are not that many variables that can be introduced by an installation crew. Especially when they are monitored an prescribed stages along the way.

Lastly, some more forward thinking labs take the additional step to retail a sample of tested materials for future reference.

Personally, I think it's excellent that you look at data. More people should. That's why PAC, Kinetics, Green Glue, Quiet Solutions, Supress, etc have materials tested.

As I recall, a greenglue wall takes about a week to cure (better TL every day for a while).

Mr. Sliva said that there were not any ASTM or NVLAP protocols in existence to restrict the client from submitting their own samples for testing. That is a stunning revelation.

That is a stunning revelation? It's quite common in any industry where 3rd party tests are concerned.

We do quite a bit of adhesive testing, and some of our customers request us to use 3rd party labs to test our material against competitive samples. Guess who submits and pays for the tests? We do. That does not mean that we in any way bias the tests - data are data.

Consumer reports makes money by selling magazines, most laboratories no not. They make money by being paid to perform tests.

Is this your only criticism of the lab in question? That they were paid by the GG company to perform the tests? Or do you have some actual criticism of the testing protocol used?

That is a stunning revelation? It's quite common in any industry where 3rd party tests are concerned.

We do quite a bit of adhesive testing, and some of our customers request us to use 3rd party labs to test our material against competitive samples. Guess who submits and pays for the tests? We do. That does not mean that we in any way bias the tests - data are data.

Consumer reports makes money by selling magazines, most laboratories no not. They make money by being paid to perform tests.

Is this your only criticism of the lab in question? That they were paid by the GG company to perform the tests? Or do you have some actual criticism of the testing protocol used?

Have you been reading my posts at all? I have no concern as to who pays for the test. I have a big concern over where the testing sample is obtained from. Simple as that. As it stands, there is little to no controls to prevent a "ringer" from being submitted to test, with this "ringer" having much better attributes than the regular retail version. When millions of dollars of sales are at stake, the propensity of fraud and deceit increases exponentially. The world is filled with hucksters and con men and sleazy businessmen. For all we know, the Greenglue people could be the reincarnation of Mother Teresa, but I can also picture numerous scenarios where they can submit a doctored piece of bonded GG drywall for testing.

Easy, I'd still recommend you contact the lab and ask about retained samples. And perhaps broaden your angst beyond one product and company. There are dozens of companies manufacturing hundreds of acoustical materials and all use the same labs with the same standardized protocols.

It does not take a moron to figure out that if GG was able to have a secret lab formula that they could pull the "switcheroo" on the "guillible" lab - that they could then sell that forumula as the premium GG for a high end markup to those willing to pay for supreme performance rather than just value.

"The world is filled with hucksters and con men and sleazy businessmen"

And so are the forums full of trolls posting anonymously without repercussions. Where you a competitor making these accusations against GreenGlue - they could easily take you to court.

The fact that you have acoustic engineers specifying the product in their designs - when they could get sued to the point of losing their engineering firm if the performance is not as specified or if the customer finds out their "independent consultant" was not performing independently - should be sufficient enough for you as a DIY to know the gunk works. Try to find a counter example of a building product with more independent credited lab tests of their product in different configurations against competing products. If you were working as a professional engineer and your boss asked if you finished the wall design yet - and your response was consumer reports has not tested any of the wall systems yet - you would be fired on the spot.

Fitting the price into your own value proposition for your build is a personal matter. If the stuff is too expensive - then simply give up some space and build a double floating isolated wall. The only increased cost there is more 2x4s.

Some folks just enjoy the sport of being contrarian.

Ted and Kras - I for one appreciate the effort you guys make answering questions and being informative. You both have far more patience then me.

How do you get 15 cases? Two 9x16 walls, two 9x20 walls and a 16x20 ceiling is about 5 cases @ 2 tubes per sheet. Many choose 1 tube per sheet given it is ~75% effective.


I need 15 cases because my space is three times larger than your arbitrary example.

bphogge, I realize you were responding to someone else who expressed concern over the cost of GG. I'm concerned as well. Because, like most people, I'm not made of money.

To everyone here, when I first discovered forums talking about Green Glue, they were professional recording studio/engineer forums. I soon discovered AVS while looking for more information on GG. I was as skeptical as the next guy. I still haven't met anyone personally who has actually used it, so I haven't experienced any results first hand. However, I haven't found anyone proclaiming it as a scam anywhere either. In two years time, I'd expect if it were bogus, we'd all know by now.
Ted would have a bit harder time hanging around forums this long without catching flak from the pros if this didn't work as advertised, let alone people who are skeptically reading about Green Glue for the first time. I grilled Ted pretty hard a couple years ago, as well as others associated with it, and people who've actually used it.

Sure, I'm making a leap of faith by spending a couple grand on this particular product versus other forms of "viscous elastomeric compound", but I can only go on the information available. There simply isn't anything else I've been able to find that presents a better alternative.

Besides, the last thing anyone needs is someone like me not being satisfied with their claims.
;)

I'm going for it, and you can bet I'll let you know how it turns out.

Sorry, I misunderstood your room size. I was referring to the dimensions in another post I guess:). I used GG in my build. I'm very pleased with my results but can't honestly say how key the GG was.

I paid great attention to caulking and isolatating HVAC. I used double studs
and isomax clips for the ceiling. After one layer of 5/8's the sound proofing was great. Could just hear some LFE in the room above and nothing on the second floor.

Since I had already received my GG and the second layer of 5/8's was already purchased and in the basement I went ahead. It improved the low frequency transmission but it was already satisfactory. Now the Seabiscuit race scene at reference level sounds like a thunderstorm way far in the distance in the room above the theater. You really have to listen for it. Before it was more noticeable but not a problem.

Was it worth it? It certainly had impact and after all the effort I spent getting the rest of the sound proofing details right, I wasn't going to skimp

"The world is filled with hucksters and con men and sleazy businessmen"

And so are the forums full of trolls posting anonymously without repercussions. Where you a competitor making these accusations against GreenGlue - they could easily take you to court.

What accusations would they be? Raising fact-based questions about the independent validity of the tests are now accusations? Come on now. Interesting that you bring up lawsuits when your tagline says that you are a LLC.

The fact that you have acoustic engineers specifying the product in their designs - when they could get sued to the point of losing their engineering firm if the performance is not as specified

Clearly, any consultant engineer is obviously taking a big risk by relying on test data where the source material for the test is not obtained independently and instead was obtained from the most biased source imaginable.

or if the customer finds out their "independent consultant" was not performing independently - should be sufficient enough for you as a DIY to know the gunk works.

You must be joking. So, what you're saying is analgous to.... a person can't be guilty of a crime because they must realize that they might get caught and go to prison?

If you were working as a professional engineer and your boss asked if you finished the wall design yet - and your response was consumer reports has not tested any of the wall systems yet - you would be fired on the spot.

I don't see your point here. Thorough testing takes longer so we should skip it and do the quick and dirty method?

What accusations would they be? Raising fact-based questions about the independent validity of the tests are now accusations?

At the risk of decending into the mire once again... what is fact-based about your questions? You question their ethics when they used the same test protocol as the rest of the world. Do you have an alternative proposal?

As was stated before, if they had a super alternative formula, they would sell it. The vast majority of the cost you pay for cartridge or tube-based products is not in the raw materials in the tube (that $8 bottle of expensive glue you can buy has maybe a dollar's worth of glue in it). So if they had an althernative forumlation that cost 25% more, that wouldn't affect their cost structure much at all.

... Thorough testing takes longer so we should skip it and do the quick and dirty method?
ASTM E-90 is hardly quick and dirty. :) And I would trust an independent test lab for accuracy of this standardized method more than the ad hoc procedures of Consumer Reports. Please read the ASTM test methodology before making further foolish and absurd criticisms.

At the risk of decending into the mire once again... what is fact-based about your questions? You question their ethics when they used the same test protocol as the rest of the world. Do you have an alternative proposal?

Mire? Would that be the mire of legitimate questioning of the notion of bias in the supply of source material? As for an alternative proposal, anywhere near the notion of some semblance of double blind testing would be orders of magnitude of improvement. The current ASTM methods are clearly much too trusting and leave themselves vulnerable to impropriety, as do some AVS forum members.:eek:

ASTM E-90 is hardly quick and dirty. :) And I would trust an independent test lab for accuracy of this standardized method more than the ad hoc procedures of Consumer Reports. Please read the ASTM test methodology before making further foolish and absurd criticisms.

The lab might be independent but the test itself sure isn't, based on where the item to be tested is sourced from. Can't you see that? Clearly, there is much less room for chicanery with a Consumer Reports test than a ASTM test. As for me making "foolish and absurd criticisms", I want to thank you for making me laugh today. Could I be sensing a lot of ownership bias on this thread?..."I already bought it, so therefore it must be effective and reputable."

The lab might be independent but the test itself sure isn't, based on where the item to be tested is sourced from. Can't you see that? Clearly, there is much less room for chicanery with a Consumer Reports test than a ASTM test. As for me making "foolish and absurd criticisms", I want to thank you for making me laugh today. Could I be sensing a lot of ownership bias on this thread?..."I already bought it, so therefore it must be effective and reputable."
Go away, Troll. You haven't a clue what is involved in real-world testing.

Is the testing methodology perfect? No.

Would true double blind tests between competing products with all products bought, assembled, and installed by independent labs give me more confidence in the results? Probably, a bit.

Would those tests cost much more for the company (and therefore the customers)? Lots. Especially when you look at the variety of tests being done and factor in storage during the 'curing' period.

Are the green glue tests more comprehensive and convincing (to me) than the tests done by it's competitors? Absolutely. The info on the Green Glue site (tests, suggestions, methods, you name it) has gone a long way to convincing me that these guys believe in their product and that it's a worthwhile addition to my HT.

Clearly you have the right to your opinion. Nobody is forcing you to use it.

I think some of the reaction to your posts comes not from your comments that 'the tests aren't double-blind, etc.' (which is true), but from the (perceived, even if not intended) implication that the Green Glue guys have taken advantage of the testing methodology to fudge the results.

A few questions:
1) A few posts have talked about not doing just the ceiling by itself b/c of "flanking noise." The GG website also mentions the same thing. Has anyone ever tried it to see if doing just the ceiling really does make a difference?

2) My room has two sides that are against concrete, one has blackboard & staggered studs, and the other is a standard interior wall (which includes part of the wall for my steps going upstairs). All the walls (and the ceiling) are filled w/ insulation and I have solid core doors (one for walking into the room, the other for accessing the wires in the HT Equipment closet) would I just need 1 tube/sheet for all the walls except the standard one, and use 2 tubes per sheet on the standard wall and ceiling?

3) Is the AVS Forum discount still in effect?

Thanks!

A few questions:

3) Is the AVS Forum discount still in effect?

Thanks!

Yes, as of last week when I ordered three more cases.

The lab might be independent but the test itself sure isn't, based on where the item to be tested is sourced from. Can't you see that? Clearly, there is much less room for chicanery with a Consumer Reports test than a ASTM test. As for me making "foolish and absurd criticisms", I want to thank you for making me laugh today. Could I be sensing a lot of ownership bias on this thread?..."I already bought it, so therefore it must be effective and reputable."

Consumer Reports makes up their own tests. The lab does not. Consumer Reports decides what instruments to use for the tests. The lab does not. Consumer Reports decides how to report its results, with absolutely no way for us to determine what technique they used. The lab does not. I could write this all day long. I'd much rather have lab tests, even if they were only STC results, than Consumer Reports types of tests.

In the past 90 days, I have submitted material for ASTM E330, ASTM E-90, 24CFR3280.401, ASTM D6815, ASTM E455, ASTM E72, ASTM E661, D1037, D1761, D3043, D4442, D790, D695, D638, D4442, D828, D5034, D3045, D2718, D2719, D3500, D3501, D5456, E96, C271, C272, C273, C297, C365, C393, C481, NFPA 286, ASTM D1037, TAS201, 202, 203, and ASTM E2126-07a.

Here's what I know ... there's a troll on board that doesn't have a clue about certified labs (ANSI, ISO, NVLAP or otherwise), materials testing, protocols, processes, audits and methods. Further CR reports are biased in their very nature of data acquisition, they are largely subjective, methods and metrics will not only change from year to year, test to test, but in the middle of a test. If CR was soooo good and reliable, they'd have ANSI certification as a test lab/facility and would be taken far more seriously than they are. Their format, however, certainly is somewhat profitable.