Not sure if my vapour barrier is done right or in the right spot. Can you tell me what is right?
I live in Alberta, Canada (great white north). I built a new house myself and wanted extra insulation. I purchased 1″ styrofoam that has foil on both side which passes as a vapour barrier (P2000 is the manufacturer).
I built a normal 2×6 wall with 3/8″ OSB for sheathing. I put the 1″ styrofoam over top the sheathing from the footings right up to the eave. My house has a cement basement with a walkout which that portion is wood and is a storey and half. I put R-20 batts in the wall then drywall with no vapour barrier on the inside as per what the guys told me even though I questioned this many times but they said not to double vapour, even though I know it should be to the inside.
The ceiling has 1″ styrofoam on the bottom side of the rafters then strapped with 1×4’s then drywall or tongue-and-groove fir.
I noticed frost building up on a wall that had no drywall on it yet, so I questioned the P2000 guy. The guy said because air could get to the batts it was causing the frost, as soon as I covered it with poly it was OK.
I have a test hole on the main floor ( I was mad about the frost and punched a hole in the wall, now covered with tuck tape and a picture) and I checked it this winter and the OSB had frost on it. I phoned and questioned this and they said that was normal, but I don’t believe them.
Can anyone give me advice or guidance for this situation? I was trying to get a better insulated house but not sure if I did because there is no air gap on the outside walls. I was doing what they said because they have done it this way on several houses, but now their literature shows it differently.
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