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Tried spray foam insulation in my attic and regret it 6 months later
I insulated my attic myself back in March with closed-cell spray foam from Lowe's. The R-value seemed great at first and my heating bill dropped about 30 bucks a month. But now I'm dealing with trapped moisture behind the foam and finding mold spots on the roof decking. Is DIY spray foam actually a bad idea for most houses or did I just mess up the prep work?
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emma_jones15d ago
And the thing about closed cell foam is it really seals everything up tight. If there's even a tiny leak or moisture source up there that stuff isn't going anywhere. It just sits against the wood and rots it out over time. Open cell foam lets moisture breathe a little more but still risky for DIY. I think most houses need a professional to check the attic first. Air sealing and ventilation have to be perfect before you spray anything.
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Respectfully, I see it differently. A lot of the horror stories with foam come from bad prep work or the wrong foam choice for the climate. Closed cell is great for sealing but if you didn't have a vapor barrier or proper venting before spraying, you're asking for trouble. Plenty of houses do fine with DIY foam as long as you take the time to seal every crack and check for existing moisture first. The mold is a sign something was already wet before you sprayed, not that the foam itself is the enemy.
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