Hi, I have a friend who's about to "button up" the shell of a garage; that is, to insulate and install interior sheathing.

His goal is a studio for acoustic guitar/vocal with recording and playback in the same space.

Dimensions are 13'W, 19'L, ceiling 7'H at wall, 9'H at peak.

He intends to stuff the 4" deep studs with 4" rockwool, covering it with 6 mil polyethylene vapour barrier. For the ceiling joists he'll use rigid styrofoam for greater R value; it will not require a vapour barrier, but he'll put it on anyway.

For wall sheathing I'm suggesting alternate 24" wide panels of 1/8" plywood, 1/4" plywood, and cloth---each spaced out 1" from the vapour barrier.

Very quiet neighbourhood, so no concerns about exterior noise, and such quiet music shouldn't bother the surrounding homes...

The ceiling insulation won't---I believe---absorb bass, so I don't know what sheathing to put on. Perhaps drywall with some exterior bass trapping would be best?

He wanted to use drywall everywhere, I believe the above will perform better.

If all these panels work as hoped, will he still need additional (corner) bass trapping?

Comments welcome....

I have 10" of stirofoam SM on my roof,and I can hear a raindrops fall,and produce about 60 dB of noise.If He is recording quiet music,and lives in an area with high rainfall,that could be an issue.

I agree about the styrofoam. Use fiberglass or mineral wool in the ceiling too.

Your friend could simulate wood panel bass traps on the walls, but if he does that he should caulk all of the seams inside the cavities to make them air tight. He'll still need fiberglass type absorption at the side-wall and ceiling reflection points.

--Ethan