Green Glue for sound insulation

[grahamboyd]

Hi,

On a recent post someone mentioned using the product Green Glue as a cheap way of insulating a cinema room. I have an older house with sandstone wall and a cavity then lathe and plaster. I am well aware that the best way to sound proof is to build another stud wall and insulate the gap however this is not an option – size of room and cost.

Could I drill holes in the lathe and plaster and squeeze in the Green Glue to fill the cavity and therefore soundproof? Or would doing this cause dampness as air could no longer flow. How effective would using Green Glue in this way be?

I suppose it’s useful to use it also to fill cracks in old floorboards with Green Glue before putting down underlay and a carpet?

Advice appreciated.

Thanks

 

[Chewy]

I'm afraid you've got the wrong end of the stick with regards to the use of Green Glue.

Green Glue is a damping compound that is designed to be used compressed between two flat surfaces. It reduces sound trasmission by reducing the ability of a soundwave to trasmit via vibration through solid objects.

In your case, you would need to purchase high density acounstic plasterboard (say 19mm plank boards), cover one side with Green Glue, and then fix the board onto the existing wall that you want to soundproof with drywall screws.

This will have some sound proofing effects, but the final result may be minimal. A better system would be to use Genie clips and furring channel over the top of your existing plaster board, and mount two layers of plasterboard onto the channel (one at 12.5mm, and one at19mm) seperated by a layer of Green Glue, applied as described above. You would be looking at losing around 70mm room width off each wall, but I'm afraid that is the case with all soundproofing options.

A good resource (and place to buy) is here:

http://www.soundstop.co.uk/solutions/wall_solutions/

In terms of sealing gaps between floor boards etc (and it is very important to seal any and all holes and gaps when soundproofing), you need acoustics sealant. The Speedline stuff is pretty good:

http://www.insulationexpress.co.uk/Sealant/Speedline-4-Hour-Fire-Rated-Acoustic-Mastic.htm