Get Help from Bob Vila
- Give-Aways & Offers
- Monthly Must Do's
- DIY Project Ideas
- Step-by-Step Guides
- Inspirational Photo Galleries
It's hard to say but if the air entering, or exhausing or gathering at or around the vent, is warm/hot, AND if there's moisture in that air, then it's possible that this is the cause of the mold.
Mold/mildew needs warm, moist air to grow. It doesn't have to be occurring constantly. It could come and go. In fact, I get mildew on the backside of my home every year. It doesn't occur in Winter but it does occur in Summer. Point is - Find the source of the warm, moist air, and you'll find the cause. As to what you should do about it, yes, perhaps a low-powered gable fan is OK. You only need enough draw to pull the air out. DON'T suck air into the attic! This would most likely add to your problem.
Do you have a bathroom vent that's exhausting into the attic space? If so, this is bad. Is there an air 'leak' from the living space into the attic space? If so, close it off.
My best to ya and hope this helps.
Jay J -Moderator
PS: God Bless America!