Zip sheathing drywall flange – drywall as ceiling air barrier
spakhnyuk1
| Posted in General Questions on
I’m using Zip sheathing on a two story house. I plan on using a detail that Steve Baczek uses where he adds a 10-12 inch flange of zip sheathing on top of the double top plate. This allows you to run a couple beads of acoustical sealant to seal off the ceiling drywall for a continuous air barrier.
Should I add this flange the the second floor only or would I need to do this on the first floor as well?
I would think I only need it on the second floor since I have a continuous air barrier with zip sheathing on the exterior until I reach my second floor double top plate.
Any advice would be appreciated. Photos attached for reference.
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Replies
Slav, the gusset plate is only needed where the wall connects to the roof or ceiling.
Perfect! Thanks for confirming.
Can you tell me if there is a way of using this detail without drywalling the entire ceiling prior to framing the interior partition walls?
There are a few options, but what I usually recommend is running a separate air control and vapor control layer against the bottom of the trusses or attic floor joists, then install 2x furring ("strapping" in the Northeast) then drywall below that. I specify Siga Majrex or Pro Clima Intello, or sometimes Certainteed Membrain. Others install Zip or other sheathing across the whole ceiling, which has a similar result. One advantage is that drywall can proceed normally. Another is that the 1 1/2" space allows low-profile light fixtures without penetrating the air control layer.