How much frost is acceptable on the inside of the attic roof?
Question:I was up in my attic in February this year (northwest Indiana) looking for a stored item. I noticed a layer of frost on the OSB, along with a fairly significant amount of frost on the roofing nails. The home is only 2 years old. Is this normal. Also: the dryer and baths do not vent into the attic.
Answers:
You have a serious problem that needs to be fixed soon. There should be NO frost/moisture in the attic.
I would not want any moisture, to form frost, in attic. Water can crawl when it freezes and go up hill and eventually get into the attic. The roof vents should let the moisture out but when it is real cold that can be hard. I say zero but it may be hard to get your builder to see it your way. Next time you see the frost call the builder and ask him how his house could be letting moisture into the attic.
None. If it's down low on the eaves, you may have an ice dam forming on the rooftop, and melted water backing up under the shingles.
If an ice dam definitely isn't the culprit, you're leaking moisture into the attic -- either a bad vapor barrier seal, or one of your vents is (do you have any bathroom fan vents with foil flex hose? Make sure there are no tears or loose hoses).
OSB won't take much moisture before it starts to break down, not to mention the risk of dry rot to the solid framing members. You definitely need to find out what the source of the moisture is and stop it.
More Related Questions & Answers...