polyisocyan. for sound insulation?
jackplane
| Posted in Construction Techniques on
After contemplating homosote, polyisocyanurate, and others, I installed 1″ thick sheets of rigid foam w/ 1/2″ drywall over plaster on brick wall, to reduce sounds from the attached rowhouse. Not much success… any ideas?
Is rockwool/mineral wool still available, and recommended?
Thanks for your ideas.
Expert since 10 am.
Edited 4/27/2007 10:07 pm ET by jackplane
Replies
From what I understand (and that's darn little) the heavier the insulation, the better it dampens sound. There is something called "mass-loaded vinyl" that is supposed to be good. I once mentioned rock wool, but someone here pointed out it is a pain to work with. You could do an advanced search here and put in the word "acoustics" or "sound deadening" or maybe "mass loaded vinyl" and get some past discussions. I can't remember if it was Fine Homebuilding or Journal of Light Construction that recently had an article about stopping sound transmission.
Edited to add: There is also special drywall that reduces sound transmission, but the article I read said the mass-loaded vinyl was better.
Edited 4/27/2007 9:30 pm ET by Danno
One inch sheets of what covered with half inch drywall?
one inch sheets of polyisocyanurate, the rigid foam board.Expert since 10 am.
Mineral fiber/rockwool is still available, and better sound insulation than fiberglass. Not real pleasant to work with though.
zak
"When we build, let us think that we build forever. Let it not be for present delight nor for present use alone." --John Ruskin
"so it goes"
My gut feeling is that sound isolation clips on res bar would have helped the most. However, just adding components to a wall assembly can cause more trouble than they solve, as they don't always act in predictable ways (as you have already found out).
Your best bet is to find a tested assembly similar to your party wall which will give you a predicable STC rating if you include all the components diligently. Google them - there are literally thousands.
Ive built double 2x4 walls to soundproof movie room with about an inch of space between with wall studs stagered so nothing touches between walls fiberglass insulation that worked well and if you wanted to deaden sound more you could use some type of wallboard under drywall. the studs not touching between walls is what makes it work so well. sound travels through studs space stops vibration. I guess. walls cost about 40 percent more for studs. because you still use 2 layers of sheetrock and insulation adds to cost . and you dont lose that much floor space to room .Carpentry and remodeling
Vic Vardamis
Bangor Me
http://www.ravengrove.com
There is a glue / mastic with acoustic damping properties that could be used to add another layer of sheetrock onto your wall. Better than the steel channel. I don't remember the name- Green something? Also, there is a sheet rock that is made for sound control it has a sheet of something bonded to it. There was an article about sound deadening in The Journal of Light Construction (JLC) awhile back that you should find and read.
Would help if you add more rock with the mastic if it is 5/8 as it will resonate differently than the 1/2 you have on now.
I've been using 1/2 on one side of a 2 wall and 5/8 on the other and I think that it works better than each side the same.
Hope that this will help.
Edited 4/28/2007 11:43 am ET by BigBill
Yes, it is Green Glue, and it works very well for what the OP needs. I've used it in wall and in floor construction on my own place, and live with the benefits. Here is a link to their site: http://www.audioalloy.com/Bill
What kind of brick wall?
And what kind of sounds?
My thoughs are that I would think that brick, by it'self would be a good sound block.
I wonder if there are other paths where the sound is getting through.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I am not very surprised that the rigid insulation did little to help. You need something dense that will block the sound waves. Porous things like insulation do little to block the waves of sound. So, you use mass loaded vinyl, which is some form of rubber that is dense to block the sound. That will block the sound transmitted through the air. There is another type of sound that is structural borne. I was reading about it in Architectural Graphic Standards for residential construction. It is a great book. For that you need to isolate the structural members, and you can do that by resilient chanel to hang your sheetrock. Check out http://www.soundsense.com
Or you can build another wall, and cover with 2 layers of sheetrock and fill it with 'acoustical' insulation. I think a 2*4 wall exterior, with 2 layers of sheetrock with insulation, has a STC rating of 44. Which means it blocks 44 decibels of the sound. Most importabtly, Just remember that any holes to the outside has to be closed. Anysmall gaps in teh exterior wall, will drastically reduce the STC rating of the wall. Caulk, acoustical sealant, etc. The fiber glass insulation rub against each other and get rid of sound in that way. The sheetrock acts as a panel that vibrates and dissipate sound energy. Heavy curtains can also be useful when covered over windows.
And apply caulk on the bottom and tops of the top and bottom plates. and maybe another layer on the inside of the sheetrock touching the plates.
Edited 4/28/2007 5:04 pm ET by temujin
Edited 4/29/2007 11:43 am ET by temujin