Vapor retarder latex paint
Code here in 4c says you need a vapor retarder class I or II on the interior side of framed walls.
I have a rainscreen system – 1/2″ plywood sheathing with taped joints, tyvek homewrap, 1/2″ furring, then hardie panels. No rigid foam. Inside I have 2×4 studs, un-faced mineral wool insulation (ultrabatt by owens corning), 1/2″ sheetrock installed 6 months ago, kilz pva primer, benjamin moore interior latex paint eggshell. Vented attic, vented crawl.
I did the best I could to air seal the exterior (and also could have done a better job with an airtight drywall approach as I’m just now learning about that stuff) but it was not a new house being built, just a remodel which posed some issues getting to everything. We will not have a perfect air seal… We do not have a whole house fan or anything like that either. Electric heat in bedrooms, and a natural gas fireplace in living room. No A/C.
What the inspector said to me when i asked about it was basically, as long as you have pva primer, latex paint, and drywall you will be fine. I don’t know if I buy that based on what code says, and that my wall doesn’t come close to 1.0 perm.. however it is not necessarily my goal to merely ‘pass code’, I do want a healthy wall assembly as well of course.
So should I just primer over the paint with a latex vapor barrier primer sealer then paint again?
Or tear down and put kraft faced insulation?
And/Or any other recommendations.
and going forward…
What is actually going to be my best (and affordable) option for the inside of an exterior wall given my outside wall assembly/climate since I will be doing the entire perimeter of the house in time.
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