is there any point to adding another layer of drywall?

[cheapskete OCer]

Ive read all the stuff on the hat track and green glue and 2 layers of drywall, but i just dont have the height in the basement for that i used to have 1/4 wood panel on the ceiling and a wall that was 2/3 the length of the room constructed of 2x2s and the same 1/4 wood panel,

I have since torn all the wood down and the wall and have framed the new wall up to code and ran it the full length of the room and am putting in a solid core door, i also have put up r-25 insulation i had 9" of space between the floorboards and rafters and this stuff is 8 1/4" so i know that will help, my question is should i spend the extra money and effort to put up 2 layers of 5/8 drywall on the ceiling and wall or just one, my GF usually just complains about the 15" epik Knight shaking the living room floor and other things around the house

Thanks

 

[Haoleb]

Maybe instead of spending the money to do two sheets of drywall, Look into some of the drywall products that are engineered specifically for sound proofing such as Quietrock

http://www.quietsolution.com/html/quietrock.html

 

[Audioholics]

An extra layer of drywall provides almost no STC help for the money.

 

[Savant]

What's the height from floor to rafters?

 

[bpape]

An extra layer of drywall provides almost no STC help for the money.

I would respectfully disagree. An addditional layer of drywall will certainly help if done on all surfaces. The Green Glue will also help a good bit. The additional mass and the damping will significantly lower the transmission and also lower the resonant frequency of the structure making less of the content likely to excite the assembly.

Also, remember that STC does not address deep bass which is where the problems to be addressed are located.

Bryan

 

[bpape]

Sorry - didn't get to post this earlier

http://www.greengluestore.com/Articles.asp?ID=148

Note that 1 layer vs 2 layers of drywall (no Green Glue) yields 2 points of STC. That's down to 125Hz. Below that, gains will be slightly higher due to increased mass and lower resonant frequency of the assembly. Adding Green Glue to the dual layer increases STC to 52 - a significant gain in isolation.

Below 125hz -

http://www.greengluestore.com/Articles.asp?ID=136

Bryan

 

[John Hile]

cheapskete OCer,

How's your project coming along?

John
__________
The Soundproofing Company