Can I put a breathable peel and stick weather (air) barrier on the inside walls and ceiling?
Anomika SinghnOct. 1, 2018Last updated: Aug. 2, 2020
Here is my problem: I have polyurethane spray foam inside the assembly cavity of my walls and unvented flat roof ceiling. It's impossible to air seal all the joints and sistered joists with caulk or sealant because where the SPF meets the joints, the seam is thin and air goes right though the SPF and enters the joints.
I'm considering an additional air seal inside the wall by covering the ceiling with something like Henry Blueskin® VP100 or some peal and stick air barrier that will still allow moisture to dry on the inside as to not have 2 vapour barriers, but stop any air and thus condensation.