Double Soundbloc Drywall

[MikeNW]

Hi,Good Moaning
I have done a metal stud wall 75mm with 50mm slab insulation and screwed a single layer of 15mm Soundbloc board. (wall is approx. 4m X 3m)

What I need to do now is add another layer of 15mm soundbloc ..

Is it best to just use longer screws to go right through both boards into the metal studs? and I was thinking of maybe using the white foam laminate flooring underlay 5mm in between the boards OR Duralay System 10 Carpet Underlay sandwiched in between to stop any vibrations... what could I use to bond these together?


I know there is green glue and acousticel m20 and similar but they are bit pricey...

 

[endecotp]

There are numerous things you could do including resilient bars, various membranes etc. but at this point things like door openings and sound coming under, over or around the wall are likely to be more significant.

I've never seen anyone try to use carpet underlay in a wall for soundproofing. That doesn't automatically mean it's a bad idea, but normally people are just trying to increase mass.

 

[Ian H]

What about sticking automotive sound deadening to the backs of the boards between the timbers?

 

[Tigercubrider]

what tends to transmit noise is physical contact

when building soundproof walls I have floated them on 1" thick neoprene to isolate them from the floor, and kept the surfaces from each other. `if you can't have a gap, then dense material is your friend.

not sure what the floor underlay would actually do.

 

[MikeNW]

Yes thanks.. The resilient bars is a good idea then screw 2nd board to them, I could add some more 50mm insulation in there also