Inside Out Wall & Ceiling Construction

[Alex W]

I'm helping a friend build a room within a room rehearsal space in his garage, and we're following the inside-out wall & ceiling design per Left Bank and other diagrams at the SAE site. From the drawings I've seen it appears that the sheetrock stops at the top of the walls. At the interface between top of the walls and the ceiling supports this leads to a pure timber barrier, with no backing sheet rock. If sealed properly on the inside will the framing provide sufficient isolation or is this a possible "weak link"? Any advice would be appreciated.

Alex

 

[John Sayers]

Yes - That is possibly the weak area Alex. Just make sure you seal as you go.
Attached is a detail of the join

cheers
John

 

[Arthur R]

sorry - silly question. Why wouldn't you extend the vertical drywall leaf above the wall top plate so that it clads the ceiling joist?

I am thinking about an inside out inner ceiling myself and was thinking about attaching 6x2 plates on the inside of the room bolted through the vertical drywall (into the studs/top plate behind it) which would carry the ceiling joists. I figure this would be easier to seal rather than suspending the joists above the wall plate as you have decsribed it. Any thoughts?

Cheers
Arthur