John Sayers' Recording Studio Design Forum Archive

I know that in the corners where two walls meet, there is supposed to be 2 studs nailed together to form a kind of 4x4 in the space shown in my picture. In my room, though, I'm discovering that this isn't always the case, and that there's some space "behind" the studs in the actual corner.

What should I fill this space with? I don't want to use caulk cause I could end up pumping 12 tubes in there and that can get expensive. I've also heard that the expandable foam spray stuff is next to worthless acoustically. There is only a very small gap between the studs, not big enough to stuff anything through, really.

Any ideas?

You're right; the spray foam sets up pretty hard and is closed cell, so it will bridge across acoustically (bad) -

If you could drill a couple of 1" to 1-1/2" holes in one of those corner studs near the top and center, you probably could blow in cellulose insulation; this is good for acoustics, and would fix that un-insulated space as far as heating is concerned too - your stucco probably has a vapor barrier between it and the studs, so it wouldn't be a good idea to put holes in from the outside... Steve