options 1-3: soundproofing new ceiling?
Dear Brownstoners, A decrepit ceiling in our 1880’s brownstone was torn out and replaced with drywall (not the thicker kind designed to reduce noise transmission). We need to improve this because airborne noise (such as speaking, music, snoring, etc.) travels up to the floor above (very audible). And airborne noise like a phone ringing, alarm clock, loud conversations as well as some impact noise like walking can be heard from the room below (seemingly less loudly). We have a rug on the floor above and will be putting padding under it. Amazingly, there seems to be virtually no sound heard between the two upper floors above these in the house. We have been proposed the following remedies (ief I understand correctly): could you advise which one you would choose? 1) cut holes in each bay and blow in cellulose; perhaps install soundproof sheet rock on top of it. 2) cut dry wall at each bay and install sound batt insulation; perhaps install soundproof sheet rock on top of it. 3) install sound proof sheet rock on top of existing ceiling (leaving 6″ around the perimeter where molding is) and still connected to the beams between the bays with GreenGlue compound between them. I realize that there is no 100% solution, but I’d really like to get the greatest improvement to this situation. This is an important place in the house to have quiet. Any and all advice would be appreciated! Thanks!
citizenjane
in Soundproofing 8 years and 10 months ago
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10 replies
citizenjane | 8 years and 10 months ago
Dear BKLN friends, Thank you for your feedback. I had a family health emergency, so I had to put this on hold. After some research, and understanding that we do not have the resources to construct a suspended type of ceiling, we have come up with two options – which also take into account the fact that we have moulding around the room which we don’t want to lose and which is now connected with the existing sheet rock. Here are the options (after cutting out all dry wall from 6″ around the moUlding): 1) Use spray foam (4″) applied to the ceiling above (provided by Tri State Spray Foam) which would leave an inch or so of space after which quiet rock would be applied. 2) Use Roxul “Safe and Sound” heat and sound insulation (Roxul RTP is not offered on the Roxul site) after which after which quiet rock would be applied. Because we don’t want to lose the moulding, we are thinking of either making the new ceiling at the same level as the old one (which means one layer of quiet wall and not two with green glue in between) or if we use two layers with green glue, it would protrude and then another decorative moulding could be added for a smooth finish. This is all quite a learning experience, and often confusing. Any last minute feedback, especially from those who have used these solutions themselves, would be appreciated. We will start to implement on Thursday-Friday of this week. Thanks again!!!! Jane
thetinkerswagon | 8 years and 10 months ago
Slope: I did go on line and tried to find the firm for the OP. I saw the site for those folks but was not sure. this was some time ago. there are probably drawings on the ‘net on how to build a grid with breaks from the other members. I seem to remember seeing drawings when we went through this (my client opted not to do this as it took space and cost). Steve
slopefarm | 8 years and 10 months ago
tinker — was it Acousitlog? I had a client (law) once who needed to do some soundproofing for a music space. He suggested something like what you and cmu are discussing. He suggested framing a “floating” ceiling with a series of little springs, and then using two layers of sheetrock laid crossways so that the seams do not line up. he had instructions for taping, etc. The gist was that the ceiling would absorb the vibration better because it floated a bit, plus the air barrier above it.
Augustiner | 8 years and 10 months ago
Noise proofing is a multi level process. One measure alone will not help a lot. And blow in insulation is nonsense. Green Glue / Quetrock are also only an add on measure for certain frequencies. It is by no means a broadband cure. For ceilings: – take off ceiling sheetrock – but one layer of semi-rigid stone wool between joists e.g. Roxul Rockboard 60, available on special order at Marjam Building supply as Roxul RTP (I dont remember exactly) for $50 a pack. You can also use the less dense Roxul AFB from Home Depot but the boards are better to work with and also give better performance. Most importantly: LEAVE AIRSPACE BETWEEN SUBFLOOR AND INSULATION. And a 2nd airspace between insulation and Sheetrock ceiling. Then use 3/4″ sheetrock for your ceiling. If you want to make the $500 investment use rubber isolators tracks. That will surely perform better than Green Glue. You might want to double the sheetrock for better performance. If you want to go pro then: Make sure the sheetrock ceiling is seperated to the walls only by caulking. If you want the real deal then insert 3-4 steel joists to catch low frequency vibration. And even more: take out all your existing walls and disconnect from the ceiling 🙂 And so on … sorry got to go now.
thetinkerswagon | 8 years and 10 months ago
I like cmu’s term “disconnected membrane”. when I spoke to the acoustical engineer, a lot of what he was saying had to do with breaking the paths of travel by off setting studs and making a complete new ceiling and joist system, none of which touched the old. in essence making a box in the room. labor intensive and pricey but there were some less expensive and partially effective options, see what rick says. also, the acoustical engineer spoke to me for quite a few minutes full well knowing that we did not have the budget to hire him. Maybe he does most of his work in commercial settings and did not mind answering questions from someone working on a room. I cannot recall his name but I seem to recall he was located on the lower east side – st marks place keeps popping in my head but I may be wrong. you may try to seek him out. Steve
cmu | 8 years and 10 months ago
In effect leaving a 6″ gap does 2 things: leave a path for the sound, and create an unbalanced, heavier-in-the-center membrane which might act as a drum. So, no. Drywall needs to be thoroughly caulked at the edges with sound-insulating caulk at a minimum. The best way to reduce sound is to create a second disconnected membrane. If you can give up 4-6″, I believe using the type of grid used for false ceilings, supported by wire (hence the disconnection) then screw 3/4 drywall as the ceiling plane, caulking the edges & joints, will work. Might be vrey labor-intensive.
citizenjane | 8 years and 10 months ago
Thanks for your quick responses. I don’t think that fixing the floor from below is an option. Do you think the proposal to have the extra sheet rock with green glue stop 6 inches away from the ceiling would stop the sound from traveling from studs or would it just create a gap through which the sound could travel? Thanks again! Jane
thetinkerswagon | 8 years and 10 months ago
mind you, your results will be better in a brick to brick layout. where you have studs running from floor to floor, the sound will travel down via studs. the engineer’s solution in that case was to create walls which were set off from the true studs. Steve
thetinkerswagon | 8 years and 10 months ago
simply insulating between the joists provides minimal help as the noise travels through the wood floor above and into the joists and then into and through the rock. I suspect that applying green glue and then rock on top of that, may be a solution as you are creating a break between the two solid surfaces. in the past one solution was to install a second set of joists that did not touch any of the structure above (be it floor or joists; they would run across the building to pockets on each brick wall) and hang new ceiling on that. that sort of isolation did the trick. this is really not my thing. a number of years ago – before the green glue or whatever it is was around or known, I had consulted a sound engineer (he is still around and working out of lower manhattan) and he talked me through the process. at the time it was a separate joist system onto which was attached the ceiling. Steve