Hi All!

I am need of a drywall contractor or soemone who knows how to install green glue over existing drywall on a cieling. So basically a drywall installer that knows what green glue is. I live in downtown denver and can't seem to find anyone who knows what this stuff is.

I live in a condo and my neighbors above make huge amounts of noise above me, mostly impact noise, and I just want to reduce it a bunch. I am just looking to do my bedroom about 130 sf. see how it goes then maybe do the rest of my condo. 650 sf total.

Currently there is no insulation in the ceiling or walls. Is it worth it to have cellulose blown into the existing drywall or just skip it and do DD+GG?

Or do I need to tear down the existing ceiling and do a hat channel? I am tring to avoid this because of cost.

They have carpet in their bedroom but, the floorboards creek very badly and shift around. They have a really cheap carpet pad too. I have already tried working with them to no avail.

I was quoted $350 to have cellulose blown into my ceiling. I think the loose fill kind?

Any help or input would be appriciated.

Thanks.

The cellulose should help a little. As for finding a contractor, don't worry about them know what GG is in advance. Just tell them you want a second layer of drywall installed where there will be a silicone like substance put between the layers. Yes we know that GG isn't silicone and isn't glue. But why confuse the contractor. You just need to be willing to supply the GG and show them how to put it on the sheet.

Do you think I should even bother with the insulation? Use the $350 for something else? Is there any other kind of insulation i could use?

Thanks for you reply.

I understand your concern over not wanting to tear down the ceiling and put in hat channel, but if you are doing work on the ceiling already (putting a 2nd layer of drywall up), it's not that much extra work. Demolition is easy. That said, you'll pay twice as much to put up 2 layers instead of just 1. But youwoudl save on insulation sice you could putup batts while the drywall was down.

I'd read the GG website for impact noise/creaking floors; since it isn't a problem in my theater I did not do much research on impact noise. As for finding a contractor, I suspect most here had the same experience I did - my drywall contractor had never heard of green glue. But I described what is was and how to install it and it did not cause any problem at all.

You really have to treat this noise at the source before it travels into the framing. That's the tough part. Best approach is:

http://www.soundproofingcompany.com/media/avsforum/upgradingFloorDiagram.gif

I guess my question is this: What is the best bang for the buck. we are talking a 130sf ceiling. just putting up another layer of drywall + GG. Or adding blown in insulation first then dd + gg. Or, is it woth tearing down the ceiling and using hat channel and sound clips and insulation?

The problem is i would like to do the same treatmnet to the rest of the condo another 500sf. I also don't have an endless supply of money.

Thanks Everyone for your input.

another thought. It sounds like you are familiar with the people above, since you know about their carpet and pad situation... If it is mainly squeeks, why not get finish nails, and pound them into their floor into the floor joists, then pull on the carpet, and that will pull the carpet above the nail head, and the squeeks should stop or be very reduced. All in all a much cheaper solution. If it is still an issue, you can go further into drywall and insulation solutions, and you would only be out hte price of a few nails.

yes, but the problem is impact noise also.

The only option that will help impact noise is resilient channel/Hat Channel. It creates a mechanical separation that helps to dampen the transmission. Quietrock and GG will not help impact noise, I put up Quietrock for high frequency noice like voices and T.V. knowing that it would have little effect on low frequency and no effect on impact. Ted White posted the best solution but that's a lot of work.

The only option that will help impact noise is resilient channel/Hat Channel.

Adding a lot of mass and damping it will help quite a bit. That would be double 5/8" type of mass. But at that point the vibration is already in the framing. Same with pure decoupling. We're not treating the vibration at the source in either case, which is preferred.

Ted White,

How much do you think your method would cost installed ~130sf bedroom? I am afraid to ask.

Thanks.

would just adding green glue and another layer of drywall make it tolerable? I am on a bit of a budget.

Ted White,

How much do you think your method would cost installed ~130sf bedroom? I am afraid to ask.

Thanks.

Maybe $325 + labor including drywall and insulation

would just adding green glue and another layer of drywall make it tolerable? I am on a bit of a budget.

I would suggest 2 layers of rock, and skinny up on the GG. Many, many people do this.

Great!

Anyone in denver want to tackle this project? Every drywall installer I talk to wants to hang the hat channel over the existing drywall. Not the way to do things. Or they want me to use quietrock. I don't Know why this is so difficult??

Well, you should be telling them what you want. The market may not be slow where you are, but most drywallers would sheetrock your birdhouse right about now...

Also, I haven't ever met a drywaller who wanted to install quietrock a second time... Stuff works, but has some installation shortcomings.

Thanks Everyone for all the info that has been provided so far!

I am getting closer to finalizing a plan. Just a few more quick questions.

I decided that I cannot decouple the ceiling becasue of the loss in height. Currently I am at 7'10". If I drop the ceiling I would be looking at a loss of 3". It would seem really low to me. Also, I simply cannot afford to do this.

I recently cut a hole in my ceiling to see what was up there. NOTHING!! The joists are about 10" deep. It is like a giant DRUM!

So here is the plan.

1. Drill holes and fill with cellulose.

I specificaly asked for loose fill not dense pack, I read that was bad.. My question is how much should the installers fill the joist? Half full? A quarter full?

2. DD + GG. I have been told that this will help the impaact noise. Hopefully this will help.

Thanks.

You want a loose fill of insulation. shoot for 3/4 full cavity to be sure they don't over-compress.

Use 5/8" drywall

I forgot to mention that I only have 1/2" fire rated drywall screwed to my ceilng. When I put drywall over the existing 1/2" I hope that the city Of Denver will not make me get 5/8" fire rated drywall. Does anyone know if this costs more, the fire rated stuff. When you hang more thatn 1 piece of drywall in denver you have to have a permit. So much for getting this job done cheap!!

If the ceiling currently passes code, then it's good to go. Adding more drywall only increases the fire resistance. I would strongly suggest 5/8" fire code. It's heavier and only slightly more $

Thanks for all the help. I will post my results as soon as I get it done!!

looking forward to it.

If you have any recessed lights in the ceiling you may want to consider having them removed and box in around them before the drywall goes up. I had my media room in my basement setup with DD+GG but unfortunately I made the stupid mistake of forgetting to box in around the recessed lighting so I do get sound creeping through the recessed light holes :mad:.

Sorry to bring this post up one more time...

I finally foud a contractor to use drywall and green glue on a ceiling.


First, I am going to do my bedroom. The people above me have carpet and carpet pad and 3/4" subfloor above me. I wanted to put gg inbetween their joists but that would require tearing down my ceiling. I am not going to live in this condo forever so I did't want to spend the money for that. The impact sound is pretty bad, and I realize that putting green glue directly over my existing ceiling will not get rid of that much impact noise.

Here is my question:

Their subfloor squeaks really bad in some areas. Is it worth it to fix these sqeaks before having cellulose blown in the ceiling? I plan on having 2 layers of 5/8" drywall and 2 layers gg over my existing ceiling. Or do you think that all the drywall green glue and insulation will block the squeaks? The only penitration I have in my ceiling is a ceiling fan.

Thanks

I honestly don't think that GG will combat the squeaks at all, man. I believe that they'll still telegraph right through any contact points, but that's just me.

I thought that green glue was suposed to block out a lot of high frequency sounds??

No. GG is used as a dampening agent used between two high mass layers such as drywall. You don't squirt it onto where you think the squeak is and have it fix anything.

To stop floors from squeaking you would need to open up the ceiling and shim/screw the floor tighter to the joists. Alternatively, it can be done from above. With carpet floors you can screw the decking/joist right through the carpet. With hardwood floors you really can't without damaging the floor.

Cathlan,

Did you read my post?? I said i was putting 2 layers of drywall and 2 layers over an existing ceiling and blowing in insulation. I was try to avoid cutting holes in my existing ceiling to fix the sqeaks. It is not posible to fix them form above because neighbors are jerks. I thought that gg was supposed to block airborne noise at high frequencies?? Isn't that what a squeak is. Installing risc clips is not an option here because of ceiling height. Once the cellulose is blown in it would be very difficult to repair the sqeaks. I was trying to avoid having to cut holes in the ceiling and find the sqeaks because there are so many of them.

Any input would be helpful.

Thnaks.

cmfjoe, Squeaks are actually initially categorized as impact. They start off as a direct vibration, usually between a nail and a floorboard. The vibration resonates in the wood, which is why the squeaks you hear are so annoying.

As javadoc said, this vibration will travel through your joists quite effectively, as both airborne and impact noise.

Having said this, you will hear a dramatic reduction in squeaks with the ceiling you have planned. 3 sheets of drywall and 2 layers of GG is a lot of damped mass.

Thanks Ted!!

I wil attempt to fix the really bad squeaks from underneath. And then go for it with the cellulose and adding gg/dd/gg/dd to existing ceiling.

Remember to keep the density of the cellulose low. Don't over-pack.

IF you are able to apply GG+DW to the underside of the subfloor, this will go a LONG way to eliminate a squeak, as it directly removes resonance in the boards. This is great if there are squeaks everywhere.

However you should shim / screw loose boards if it is isolated to one spot (and not do the GG+DW)

Ted do you think that ripping off the ceiling and applyind 1 layer of gg/dd screwed directly to the subfloor and then adding r19 and then dd+ gg directly to the joists will be better than the blown in cellulose and and 3 layers of drywall and gg? The contractor advised my against screwing the drywall directly between the joists becasue the screws could come lose over time. There is also the additional cost of ripping the ceiling down. But then it would be cheaper putting r19 than blowing in cellulose. I am really on the fence here as to wich method to use. Seems like a lot of labor to pay someone to fit drywall in between the joists? This is just for the bedroom. The living room is hardwood above me. To rip that ceiling out would be a huge pain. Is there a much better reduction in sound if i put gg/ drywall between the joist?

Thanks

"Ted do you think that ripping off the ceiling and applying 1 layer of gg/dd screwed directly to the subfloor and then adding R19 and then dd+ gg directly to the joists will be better than the blown in cellulose and and 3 layers of drywall and gg?"

Yes. Both scenarios are adding the same amount of mass to the system. However scenario #1 addresses the vibration right at the source.

"contractor advised my against screwing the drywall directly between the joists becasue the screws could come lose over time."

Every ceiling in America is held up with nails or screws... Also, Green Glue will dry and that drywall isn't going anywhere.

It is cheaper to install batt insulation rather than cellulose, as you say. Lastly, you could at least install wood furring strips to the joists every 24". You would have space since this scenario has 2 sheets of drywall on ceiling, not 3.

While the wood furring won't decouple, per say, it will allow more flex due to the 24" furring spacing rather than your current 16" spacing.

If someone invented some sort of penetrating, flexible glue that you could squeeze/inject where you hear the squeaks, they'd be billionaires. I think your challenge will be pinpointing exactly where the floor above is squeaking, and hitting it with a screw. I just went through this with my basement stairs, and even with a very willing assistant, it was laborious and tedious work. Since you already mentioned that your neighbors are 'jerks,' so I doubt they'd be very compliant to helping you with spotting the squeak. However, if you could get their help to step where the squeak is, and then attack that area, greater success will be had.

Now, driving a screw into neighbor's foot... while satisfying on a sinister level, try and avoid that. ;)

If someone invented some sort of penetrating, flexible glue that you could squeeze/inject where you hear the squeaks, they'd be billionaires.

You mean like expanding foam? ;)

Although one must be careful with expanded foam. Make sure there is plenty of room to expand!

Ah but the foam is a conductor, and reduces the effective volume of the air cavity, thereby raising the resonance point and seriously reducing our ability to reduce low frequencies.

is it worth the extra effort and $$ to put gg/dw/gg/dw directly on the joist?

Not on the joist. On the underside of the subfloor. As shown here: http://www.soundproofingcompany.com/index.php?/solutions/neighbor_noise/neighbor_noise_ceilings

"Worth it" is really subjective, but there have been so many super pleased people that have done this over the years. I really recommend it.

sorry, i said joist and i meant subfloor. So it is woth it to put 2 layers of drywall and gg directly on the subfloor?

Yes. Plus you get proper insulation and the chance to install the wood furring strips.

All great things

Ah but the foam is a conductor, and reduces the effective volume of the air cavity, thereby raising the resonance point and seriously reducing our ability to reduce low frequencies.

If we are just using the foam to help seal the gap (effectively just using it as a "glue" between the joist and the subfloor) causing the squeak is this really an issue? I didn't mean filling the entire cavity.

I don't think foam will do all that much. The squeak will still squeak, still conduct through the joists, and noise overall will be louder from both above and below.

I have a few more quick questions before I let loose on this.

The subfloor above me is 3/4" plywood. My contractor wants to staple the 1st layer green glue and drywall inbetween the joists and then staple the second layer to the first layer. Does anyone see any potential problems with this? He wats to do this because it will be faster. I thought it was supposed to be screwed up? Maybe he dosn't want to screw up through the subfloor?

Also, my contractor wants to charge me $400 to remove the existing drywall ceiling. seem a bit steep to me. I think that I should be able to do this myself. As far as i know I would just use a utility knife and cut in the seems between the wall and the ceiling and becarefull not to damage the wall. Should I be very concered about damageing the walls?

Thanks.

If the contractor compresses the Green Glue while stapling that would be "OK" but not optimal. The screws as you pointed out, compress the Green Glue. This is important. Also, any fasteners will need to go all the way to the subfloor. You can't staple the second layer into the first.

Screws of the right length will not protrude upstairs.

I have a few more quick questions before I let loose on this.

The subfloor above me is 3/4" plywood. My contractor wants to staple the 1st layer green glue and drywall inbetween the joists and then staple the second layer to the first layer. Does anyone see any potential problems with this? He wats to do this because it will be faster. I thought it was supposed to be screwed up? Maybe he dosn't want to screw up through the subfloor?

Also, my contractor wants to charge me $400 to remove the existing drywall ceiling. seem a bit steep to me. I think that I should be able to do this myself. As far as i know I would just use a utility knife and cut in the seems between the wall and the ceiling and becarefull not to damage the wall. Should I be very concered about damageing the walls?

Thanks.

Are you sure the plywood above is 3/4"? Most plywood subfoors are 5/8". 3/4" would be more probable if the subfloor was OSB. Not that it matters much, but the lack of that extra 1/8" might cause a protrusion of the fastener chosen into the "jerks" above. :eek:

Hi cmfjoe, I have the same problem! Jerks living upstairs!! Could you please let me know of what you decided to do and if it worked and how much it cost?


Thanks!

Joe, I'm in the denver area as well. Did you find green glue in denver? If so, would you mind pm'ing where you purchased it?

I found one place out in Aurora, but was hoping to find something closer.

I am experiencing the exact same situation as cmfjoe. I really wish he had followed up to share his final decision and the results. Everything he said about his situation applies to me as well (already low ceilings, lots of impact and airborne noise, squeaks in a few spots only, a LOT of square footage that needs to be soundproofed, upstairs neighbor not willing to help, minimal insulation). Ted has suggested that adding 2 more layers of drywall with 2 layers of GG would help significantly. I am not looking to build a home theater. I just want "satisfactory" or "adequate" soundproofing. By adequate, I mean that I don't mind being AWARE that the person above me dropped an apple on the floor, but I don't want to hear a big thud either. The cost seems to go up significantly when doing interventions that involve removing ceiling. I am looking for bang for the buck, but I fear being disappointed with the finished result of 3 layers of drywall and 2 layers of GG. Basically, will I still hear thuds or just pitter patter when someone walks briskly above me?

Guys,

Have a look at this article. http://www.soundproofingcompany.com/solutions/soundproofing_ceilings/

It discusses the physics involved in the impact noise phenomenon. You may not be building a theater (airborne noise challenge) but the impact noise is the worst problem we deal with. Much different to have someone actually pounding on the floor above than to have a tape recording of someone stomping on the floor. Much different and obviously much more difficult to solve.

Wait a minute ... very easy to solve... take the hammer they are using to bang on the floor, execute a tap to the side of their head ... hammer noises stop. (Dont really do this!)