New construction air sealing question
New construction in CZ3 (southeastern NC, warm humid).
2×6 exterior walls @ 24″ OC with ZIP sheathing.
Vented attic with gable roof using raised heel trusses.
Dense packed cellulose in the walls and blown cellulose in the attic.
Air barrier is the exterior ZIP sheathing and the ceiling drywall.
What is the best way to air seal the ceiling drywall to the top plate of the exterior wall? Air sealing the ceiling drywall to the top plate of the interior partitions? Also, does truss uplift affect this?
I found an article on Fine Homebuilding that mentions using a 3/4″ cap plate on top of the exterior and interior top plates to give the ceiling drywall a surface to seal against, but this would also involve using 3/4″ furring for the entire ceiling because of the gap created by the cap plate.
This seems like a practical solution, but would it cause issues with drywall cracking and separation due to truss uplift? Is there a better way without have to use furring for the entire ceiling?
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