Vapor barrier / retarder in wall between attached garage and house, zone 4A?
BrunoF
| Posted in General Questions on
I am in central North Carolina (mixed humid) and noticed that the insulation crew installed unfaced batts in the shared wall between my garage and house. For the rest of the house, I have siding, house wrap, OSB (taped and sealed), fiberglass then drywall for my assembly. in this shared wall however, I will not have any OSB, siding or housewrap; just drywall on both sides and insulation in the middle.
Is this an acceptable assembly or should I have a vapor retarder / barrier in that shared wall?
Thanks!
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Replies
I'm not a builder (sort of) but I would not want the risk of car exhaust getting into my house. The barndominium I'm building myself right now as two technically-interior walls that I'm treating as exterior for the same reason. We're talking sheathing, tape, and even spray foam to make sure I'm good to go. Then I'll just put a piece of drywall on that
BrinoF,
My reading of the IRC is that a class 2 or 3 vapour retarder is required in climate zone #4.
Thanks. So I guess priming and painting would technically count as a class iii VR?
BrunoF,
Yes. Two coats of latex paint on drywall is around 5 perms.