Author Topic: Wooden Wall  (Read 3543 times)

barryo78

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Wooden Wall
« on: September 09, 2014, 04:38:26 PM »
Hi All,

I'm looking to improve the soundproofing of my bedroom. We live on a relatively busy road but about 3 feet away from the traffic. While we have adjusted to the traffic noise I would still like to reduce it a bit.

The room has two walls that are concrete and brick that I assume are relatively soundproof. The other outside wall is wooden framed with wood cladding on the outside and plasterboard (I think that's drywall in American) on the inside.

What I'm thinking of doing at the moment is removing the plasterboard and stapling some MLV (as close as possible to the outside cladding) between the studwork, followed by some Rockwool insulation and a small air gap. I was then going to put acoustic plasterboard back in place of the original, and maybe another layer with Green Glue sandwiched in between the layers.

Not sure about the Green glue and second layer as it is quite a small room and I want to avoid making it any smaller.

I was hoping someone could ether offer an opinion as to the likely effectiveness of my current thinking, suggest anything that will help, or point out anything that I was suggesting that will not make enough difference to be worth the effort.

Sorry for the rambling, any help would be much appreciated.

Barry.

P.S the window will have acoustic glass secondary glazing and the 4th wall is an internal wall.

Randy S

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Re: Wooden Wall
« Reply #1 on: September 09, 2014, 07:31:33 PM »
The best approach would be to use 1/2" cement board in between the studs and caulked before the insulation.
add the insulation then use mass loaded vinyl staple to studs covering the entire wall and seal with acoustical caulk.
once this is done use resilient channel RC-1 followed by 5/8" drywall, leave a 1/4" gap around the perimeter and fill with acoustic caulk.

You will only lose 1 1/4" from the stud and this system will work just fine for traffic noise this close to your home.

with out the decoupler you might not get the desired reduction your looking for.

Randy S.
Randy Sieg

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Ph. 760-752-3030
Fax.760-752-3040

barryo78

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Re: Wooden Wall
« Reply #2 on: September 09, 2014, 08:53:34 PM »
Hi Randy S,

Thanks for the reply. I was hoping to loose less space than that. I know it doesn't sound much, but my house is very small. It sounds like it will make a big difference though so I'll have to decide on which is more important to me I guess.

Hadent thought about cement boards between the studs... Probably better and cheaper than mlv for that job.

Thanks again

Barry

Randy S

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Re: Wooden Wall
« Reply #3 on: September 09, 2014, 09:06:54 PM »
you need to use both, what you need to understand is mass law.
Mass law states you must double the weight or the density of the partition just to see a 5db drop or a 40% reduction of what is being heard. The only way to void mass law is to create the complex structure using channel or double frame system.
especially with street noise the reduction under mass law is still minimal because it is low frequency not high frequency.

Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

barryo78

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Re: Wooden Wall
« Reply #4 on: September 09, 2014, 11:02:25 PM »
Thanks for that. I think I roughly understand the concept.

Looked up why decupaling works and I seems to make sense.

I understood it as, the vibration has to transition from a low mass medium which finds it harder to then vibrate the high mass medium.

I'm probably wrong but at least I now know it's importence.

I won't be working on it for a while yet but like two plan ahead, so might have some more questions when start.

I did think of another question when doing some research. How would you deal with the window opening? I can't figure out how thus can be plastered without creating a flanking path.


Randy S

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Re: Wooden Wall
« Reply #5 on: September 09, 2014, 11:27:58 PM »
you need to leave the 1/4" gap from sheet rock to window frame and caulk with acoustical caulk, you can hide this with some molding. I would highly recommend you avoid plaster coating at all costs...not good for soundproofing.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

TomYamPraKraPong

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Re: Wooden Wall
« Reply #6 on: October 14, 2014, 12:26:32 PM »

Fantastic.You are my idol.Make me for good idea.Just to do it.