What can I do about “impossible” mold on the spray foam insulation in my sealed attic?
This spring I bought a 10-year-old home in New York State. The attic is a narrow crawl space with thick, open-cell spray foam insulation on the roof, no insulation on the floor, and no ventilation. It appears that there is little air exchange between the attic and the house, and presumably even less between the attic and the outdoors.
Summers here are warm and very humid; winters are quite cold.
A month after moving in, I climbed into the attic for the first time, and found a decent amount of mold growing on the foam insulation.
It has since been looked at by a mold remediator and two assessors, all of whose reaction was “huh, I’ve never seen that before!”
The assessor suggested adding lots of ventilation into the attic, and insulating the floor instead of the roof. Several articles on this site suggest that’s rarely a good idea, especially when (as in my case) there is duct work in the attic.
Since my local “experts” seem mystified by this problem, what on earth am I supposed to do? How did the mold get into this supposedly mold-resistant attic, and how can I prevent it from coming back?
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