I just bought a new home here in Beaverton, Oregon, U.S. The walls seem to be as thin as paper. Is there any good sound deadening material that can be pumped into the walls to increase the STC? I just want to block out noises to a less noticable level, but I don't want to have to rip out this new drywall.
Answer:
Rather than ripping it all out, you might consider just making larger holes where the electrical outlets are so you can move them forward. Windows and doors are not hard to build out to accomodate. You already have 1/2" drywall there so I might not change that to 5/8" but the rest of this works very well; Sound proofing a wall or ceiling, I’ve found, is best done by creating a sandwich with lots of bulk. I apply 5/8” gypsum board (roughly taped, jointed and sanded) to the studs or joists and then 7/8” sound absorbing fibrous panel manufactured for the purpose. On top of that, I apply resilient channel (16” O.C.) and then another layer of 5/8” gypsum board. This time the gypsum board is properly taped jointed and sanded.