Is taped plywood “good enough” air barrier for T&G ceiling with flash and batt?
Zone 5 (NH)
Nearing the end of an extensive to the studs remodel of about 1/3 of my home and now it’s finally time for the ceiling. My hat is off to GBA for the amazing knowledge I’ve used throughout.
Is taped 1/2″ plywood a “good enough” air barrier before I put up my pine T&G ceiling? To the best if my abilities I taped the seams with 3M All Weather Flashing Tape 8067, but there are certainly spots that don’t have a 100% seal and I know the tape won’t hold up for all eternity. The house is old and nothing is even so the sheets are not a perfect snug fit, but pretty good. There are plenty of other areas that I simply cannot seal without gallons of caulking and years to apply it. I used plywood on the walls and ceiling for strength and to make nailing the T&G easy.
Unvented cathedral ceilings – flash and batt (3″ closed cell, R21 unfaced)
Careful attention paid to potential areas of thin foam and leaks to the outside with dozens upon dozens of cans
Lots of skylights
Lots of recessed lights
Lots of receptacles in ceiling
I read on GBA that CertainTeed Membrain could be used as my air seal, but with all the unavoidable penetrations in the envelope, is it worth chasing the plywood seams? Where should I focus my attention prior to T&G? The remodel is nearly complete so it’s literally JUST putting up the ceiling but I don’t want to miss a step.
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