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Community and Q&A

Attic Plywood Air and Vapor Barrier

kenmoremmm | Posted in General Questions on

I have been planning to use a 5/8″ plywood + tape to create my air/vapour barrier between my conditioned space and the attic. My walls are ICF and the plywood would be taped to the ICF foam.

I am in zone 6A in southeast British Columbia. It sounds like the local inspector may still want us to use a poly barrier. I wanted to avoid this because of added cost, durability, and the PITA nature of any penetrations.

Is there any code/literature that I can point to to help ease his mind? I’ve found these articles, but I would classify them as good, but not great resources:

Air vapor barrier ceiling

How Good Is Your Air Barrier?

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