“Picture framing” stud bays with sealant.
I am retrofitting my house in climate zone 6, which was built in the 80s. I had to open up most of the walls due to rodent infested fiberglass insulation throughout the house. I’m taking this opportunity to improve the insulation in the walls.
The original wall assembly (from outside in) was: cedar shingles, on plywood sheathing, 2×6 stud bays filled with fiberglass, and then a layer of poly sheeting under the drywall.
I did notice clear signs of mold on the interior of the poly sheeting.
My plan was to upgrade the fiberglass insulation to mineral wool, replace the poly sheeting with a smart vapor barrier, and in the future add more insulation to the exterior.
However, I came across some discussion on GBA about air sealing sheathing on the interior: https://www.greenbuildingadvisor.com/question/picture-framing-the-stud-bays-with-knauff-ecoseal. I don’t think my sheathing is taped or sealed on the exterior, and I was thinking of using a caulk like Contega HF to seal the studs to the sheathing from the inside, i.e. “picture framing”.
Does this make sense? or is this redundant with the interior smart membrane?
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