Wonderful resource here, every day a school day! I'm hoping to answer a question regarding my studio build. It's a two-room setup in an existing shed/outbuilding. Control room to be 3.6m x 5.1m and Live Room to be 6.1m x 5.1m. The sloped ceiling in both rooms will run from 2.4m at one end to 2.7m at the other. Here's a quick cross section of the wall and ceiling buildup:
My question is this: Is the RWA45 (45kg/m3) in the walls going to dampen the resonance of the PIR Foam insulation (I can't find density info on this) and the plasterboard, or will this build-up cause me headaches down the line/turn my rooms into giant horrid-sounding floor toms??
The reason for this buildup, by the way, is because of U-values. If I wanted to hit the thermal insulation target with just RWA45, I would need almost 200mm, and my studs are only 100mm deep. I know that PIR has no useful acoustical properties, but in this situation, its use is purely thermal and space-saving. But will it do me any harm acoustically? My hope is that because it's rather light, that sound will pass right through it. However, this could also mean that the plasterboard has little dampening applied to it.
I'd love to hear some opinions on this, especially if anyone has any experience using a room with similar walls (insulated plasterboard fixed to battens etc.)
Many thanks in advance, and let me know if you need more detail.
R
Why do you not want to use that air gap for insulation?