Tried spray foam in my attic after that leak in Portland last spring - now I'm split on it

My mom's house in Portland had a roof leak last April, and I helped her rip out all the old fiberglass batts. I pushed for closed-cell spray foam, sealed everything tight. Fast forward to August, and her AC has to run way harder, and I'm worried about moisture trapping. Guys on this forum swear by it for air sealing, but my HVAC buddy says it's a nightmare if you ever need to rewire. So what's the real deal - is spray foam worth the risk of high bills and hidden rot, or should I stick to batting?

2 comments

2 Comments

theagarcia2d ago

Painted my whole deck with leftover spray foam once, big mistake.

taylor.betty2d ago

Wait, did you actually use spray foam on a deck? That sounds like a skating rink waiting to happen when it gets wet. I mean, I get wanting to seal things up but on a deck that sees rain? Anyway, on your real question - I've had a few customers swear by spray foam for their attics but then regret it when they have to run new wires for a ceiling fan or something. My HVAC guy told me the same thing about the moisture, especially if your roof ever has a tiny leak you don't catch right away. It'll trap that water like a sponge wrapped in plastic, rot the wood underneath before you even know it.