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Should I insulate the ceiling of my basement home theater room?

post #1 of 24
Thread Starter 
I'm finishing part of my basement into a dedicated home theater but I'm doing it on a budget. That means no special acoustic treatment or anything special.

I've used R-13 insulation for the walls and I'm installing drywall for the ceiling (eg. no drop-ceiling).

Should I put insulation in the ceiling before I install the drywall? (If so, what size? The floor joists and about 6" - 12" long I'd guess).

I am trying to save money, so if there is a little benefit to insulating the ceiling than I'll probably skip it.

Thanks for any advice
post #2 of 24
I replaced the ceiling in one of my basement rooms that didn't previously have insulation. I filled the 2x12's with insulation and put up the new ceiling. It was plank T&G and not drywall but I noticed a decent change in high frequency reduction. Bass still goes though but higher frequencies are damped. To give some example - My son can practice trumpet in this room and its very tolerable in the living room above it. Before we redid the room ceiling below this would have been too loud to have guests over while he practiced.

Grant
post #3 of 24
Similar situation to mine, except mine is not a dedicated theater. I went ahead and put insulation in the ceiling above the portion of the finished area where the theater will be, which also happens to be directly under our family room that gets used a lot.

I think I used R-25 batts so as to mostly fill up the joist spaces. Even before I drywalled the ceiling, I felt it did noticeably cut down the TV and other noise I could hear coming from the family room, and vice versa.
post #4 of 24
In my last theatre/media room (prefinished before my arrival), there was nothing in between the joists - I couldn't bring myself to ripping off the drywall just to insulate it though. Movies downstairs were easliy heard from the livingroom above.
In my current scratch build, I stuffed Roxul Safe'n'Sound (mineral wool) into all of the joist cavities and then hung the sheetrock. I can honestly say that this made a significant difference in the sound transmissions from below (mid to high frequencies). I didn't double drywall or Green Glue (budget also), but do feel that if you can insulate now you should. Once the room is built, you will not want to tear the ceiling down at some later point. If you can afford it, put as much in as you can. If you wish to double up with GG or change later, then it is not as much work and extra cost & labour. Remember though, it won't do much to stop a subwoofer It's the only thing I can hear when everything's turned up!
post #5 of 24
Yes - fill it. Not only will it help with sound transmission in both directions, but it will also keep the cavity from resonating and causing frequency related issues. Also, to a certain extent, it will offer a small amount of bass control inside the room - not a bad thing since you don't seem to think you have any budget for treating the in-room acoustics. Might as well get this 'freebie'.

Bryan
post #6 of 24
Fill it.
post #7 of 24
Thread Starter 
Well, I've measured the amount of space between the floor joists and it is 9" deep which meant I could have purchased R-25 (8" deep) insulation but that was a bit too expensive for me so I went with R-19 (6.25" deep).

Will this work OK or did I screw up?
post #8 of 24
Quote:
Originally Posted by sofakng View Post

Well, I've measured the amount of space between the floor joists and it is 9" deep which meant I could have purchased R-25 (8" deep) insulation but that was a bit too expensive for me so I went with R-19 (6.25" deep).

Will this work OK or did I screw up?

Anything is better than nothing. That is what I went with in my ceiling (R19)as it is not a dedicated HT room, I just wanted a little more insulation than straight drywall. Have the drywall up and it is fairly quiet downstairs, noticably quieter than without insulation. Did the whole basement for $230 bucks...

A sound investment if you ask me. (Pun intended )
post #9 of 24
Sorry to revive an old thread, but didn't want to start a new one unnecessarily. I understand the points listed above, but I was leaning towards not insulating, and was wondering if my reasons are . . . well, reasonable.

In terms of HVAC I think not insulating will be preferable since we have a 1 zone house and our master tends to be cooler. I think the radiant heat from the finished basement will help.

Our heating ducts run under the joists. So this is the path of least resistance for sound travel. It seems insulating will do little to attenuate the sound reaching the upstairs. Right?

Thanks!
post #10 of 24
Quote:
Originally Posted by jvh4 View Post

In terms of HVAC I think not insulating will be preferable since we have a 1 zone house and our master tends to be cooler. I think the radiant heat from the finished basement will help.

I don't...

Over time the floor will be the same temperature regardless of the insulation (since it's not a perfect insulator) with both sides being 'conditioned' spaces attempting to be at the same temperature. The small temperature delta between the rooms probably gives almost zero radiant benefit. (IANA HVAC guy... tongue.gif )
Quote:
Our heating ducts run under the joists. So this is the path of least resistance for sound travel. It seems insulating will do little to attenuate the sound reaching the upstairs. Right?

Sort of, but that will depend on the placement of the vents in both rooms (distance from each other), turns in the ducts, and the construction. But some cheap fluffy insulation will deal with a lot of sounds in both directions - since it's your master bedroom above, you should be doing AT LEAST these minimum things to mitigate sound transmission. IMO...

Jeff
post #11 of 24
Quote:
Originally Posted by jautor View Post

I don't...

Over time the floor will be the same temperature regardless of the insulation (since it's not a perfect insulator) with both sides being 'conditioned' spaces attempting to be at the same temperature. The small temperature delta between the rooms probably gives almost zero radiant benefit. (IANA HVAC guy... tongue.gif )
d transmission. IMO...

Jeff

OK I buy that.
Quote:
Originally Posted by jautor View Post

I don't...

Sort of, but that will depend on the placement of the vents in both rooms (distance from each other), turns in the ducts, and the construction. But some cheap fluffy insulation will deal with a lot of sounds in both directions - since it's your master bedroom above, you should be doing AT LEAST these minimum things to mitigate sound transmission. IMO...

Jeff

I see what your saying. So I have a 12"x6"aluminum vent that runs along the spine of my house. It runs perpendicular to the joists and is therefore below them. This runs through the HT. I have 6" round vents that come out the top of that that run between joists and into each room of the house. In theory, I could get some insulation between the drywall and round duct work. but there is no mass to attenuate sound before entering the rectangular vent. So if I spend $700 on batting am I even going to see a 1 dB reduction in sound in the master above? If the sound comes up the floor vent like a speaker will I notice that some higher frequencies aren't coming through the floor?

I don't necessarily disagree with you. I'm literally on the fence. My wife is leaning towards saving the $700 for other projects. She didn't like my idea of using it for a second subwoofer. Something about counter productive . . .
post #12 of 24
Is $700 the price for the builder to do this? That seems really high for one room's worth of fiberglas batts...

Take a look at the earlier responses in the thread regarding the results. Don't expect miracles, but the reduction in resonance and transmission in the mid-range would tend me towards a "yes". That, and the fact that we're talking about theater-to-master-bedroom.

And the sound transmission of $700 worth of insulation vs. a second subwoofer - well that's two ends of the spectrum!!! biggrin.gif
post #13 of 24
Quote:
Originally Posted by jautor View Post

Is $700 the price for the builder to do this? That seems really high for one room's worth of fiberglas batts...

Take a look at the earlier responses in the thread regarding the results. Don't expect miracles, but the reduction in resonance and transmission in the mid-range would tend me towards a "yes". That, and the fact that we're talking about theater-to-master-bedroom.

And the sound transmission of $700 worth of insulation vs. a second subwoofer - well that's two ends of the spectrum!!! biggrin.gif

Exactly smile.gif $700 is just a quick back of the napkin number. I figured 1,000 sqft at $0.70/sqft was a god guess. I'll do it all myself. Maybe a compromise would be to only insulate over the HT portion. That would cut the area in half.

Anyone ever try the blow in insulation? It's typically for attics right? I ask because Home Depot will rent me the blower for free if I buy 10 bags. Looks like you're swaying me . . .
post #14 of 24
Pink R13 rolls are $12 per 25-foot roll... You can't use the blown-in insulation as the ceiling has to be in place first.

DIY this is probably <$300 for the whole space, but if you want to just do the theater area, even less...
post #15 of 24
Quote:
Originally Posted by jautor View Post

Pink R13 rolls are $12 per 25-foot roll... You can't use the blown-in insulation as the ceiling has to be in place first.

DIY this is probably <$300 for the whole space, but if you want to just do the theater area, even less...
I'm also getting ready to insulate my ht and unfinished basement. I was under the impression that a screen type material could be placed across the ceiling/floor joist and then the insulation blown in?
I don't believe r-13 would be enough, I'd go with r-30 if you can for the ceiling. That's my plan anyway
post #16 of 24
Ted White from the Soundproofing Company has consistently said to go with R-19 because you do get some acoustic isolation improvement beyond R13, but nothing perceptible if you full-bore and fill the cavity with R30. Personally, I'm going with R30 for reasons like BPape mentioned above in 2007.
post #17 of 24
Yeah, listen to Ted. You've got room for R19...(I was thinking wall thickness, not ceiling)
post #18 of 24
OK. R-19 batting it is. I'm still not convinced it will matter with the vent, but for $220 I might as well do it while the ceiling is open. Thought about Roxul, but its 9 times the cost. I expected a premium, but not 9 times!

Thank you all for the feedback.

EDIT: Apparently the Roxul was an 8-pack, so it's only a 12% premium to go Roxul. Just didn't want others to be misled.
Edited by jvh4 - 11/6/13 at 2:16pm
post #19 of 24
Quote:
Originally Posted by TMcG View Post

Ted White from the Soundproofing Company has consistently said to go with R-19 because you do get some acoustic isolation improvement beyond R13, but nothing perceptible if you full-bore and fill the cavity with R30. Personally, I'm going with R30 for reasons like BPape mentioned above in 2007.

This actually brings up an interesting point. I read (but cant confirm accuracy) that installing batting that contacts both the subfloor and ceiling drywall (ie stuff the entire void) can actually transfer sound and negate the soundproofing advantage of installing it in the 1st place. There may be other advantages of doing it.
post #20 of 24
Quote:
Originally Posted by jvh4 View Post

This actually brings up an interesting point. I read (but cant confirm accuracy) that installing batting that contacts both the subfloor and ceiling drywall (ie stuff the entire void) can actually transfer sound and negate the soundproofing advantage of installing it in the 1st place. There may be other advantages of doing it.

That's total poppycock! There's a ton of air in the insulation and it's comprised of individual glass fibers - not continuous. The limited amount of vibration that makes it through a thick ceiling has virtually no way to translate that vibrational energy to the other side. Translation...if you go with R30 out of choice, you'll be just fine....
post #21 of 24
Quote:
Originally Posted by jautor View Post

Is $700 the price for the builder to do this? That seems really high for one room's worth of fiberglas batts...

Take a look at the earlier responses in the thread regarding the results. Don't expect miracles, but the reduction in resonance and transmission in the mid-range would tend me towards a "yes". That, and the fact that we're talking about theater-to-master-bedroom.

And the sound transmission of $700 worth of insulation vs. a second subwoofer - well that's two ends of the spectrum!!! biggrin.gif

I agree...........................I'd have to look at receipts, but I added R-13 on all interior walls throughout my home which I believe cost was $900 +..............................heck of a lot more added insulation than one room.
post #22 of 24
Quote:
Originally Posted by TMcG View Post

That's total poppycock! .

Me Grandmum's favorite WORD! And she was from Surrey...................................i.e. not an Eastender...................biggrin.gif
post #23 of 24

opps double post.

post #24 of 24

Here in northern Utah Pink stuff R30 is only $10 more (give or take a couple bucks) than R19 for 1000sq ft. I am buying it by the rolls as this is the best price.

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