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Old 2018-02-22, 03:10 PM
BartBandy BartBandy is offline
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Join Date: May 2010
Location: Ontario/Nobleton
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Vapour barrier prevents warm moist air from reaching cold surfaces, where the water will come out of the air as condensation. Vapour barriers are always on the warm side of the wall. He may be suggesting some sort of air barrier, which is tyvek/typar or some sort of paper product. Some people put this between the concrete foundation wall and insulation. I'm not sure why.

To me, leave the builder insulation but slash the vapour barrier they installed, stud up to it, then add more batt insulation between the studs and new vapour barrier. Slash the old vapour barrier because you don't want two layers of VB for water to get trapped between. Or, get rid of all of the old insulation and use closed cell spray foam, which is what I did. Works way better in the joist cavities especially.
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