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Vapor barrier under slab at frost wall/edge of slab junction?

balamson | Posted in General Questions on

I am getting ready to pour a slab on grade. Capillary break – Roxul IS – vapor barrier – slab and the 48′ frost wall has Roxul from the top of the footer to top of slab (interior). The slab will be 3″ lower than the top of the frost wall

The vapor barrier will run under the slab and up the outer edge along the frost wall insulation. At this point I am considering using a peel and stick vapor membrane attached to the under slab barrier, running up the 3″ of frost wall and across the top? To me this would be a good way to completely block all moisture transmission from the frost wall into the framed wall and interior living space.

I can’t find anything specific to this question. Thoughts?

Thanks in advance, Brad

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  1. GBA Editor
    Martin Holladay | | #1

    Your plan is fine; I see no reason not to do it.

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