Warning about spray foam insulation in our cold winters
I had a guy from a local Edmonton company install spray foam in my attic about two years ago, and he came back for a check-up last fall. He pointed out that I hadn't left enough of a gap between the foam and the roof sheathing, which is a big deal here because of our temperature swings. He basically said, 'In this climate, you need that air space to let any moisture escape, or you're asking for rot.' I had just let them foam right up to the wood, thinking more insulation was always better. So, I had to pay to have a small section cut back and re-done, which cost me around $400. It was a real 'oh, right' moment because I was so focused on the R-value that I ignored the building science part. Now I always ask contractors specifically about vapor barriers and air gaps for our weather. Has anyone else had to fix a spray foam job because of moisture worries?