Condensation In My Bathroom Fan Light: How Can I Stop It?

Learn the one-step solution to preventing condensation in an exhaust fan light – and find out why it's happening in the first place.

LESLIE: Bobby in North Carolina is on the line with a bathroom-vent question. What can we do for you today?

BOBBY: I’ve got an exhaust fan and the light combination. And when it gets real cold back there – and I don’t have a lot of heat back there because I like a cool bedroom and the spare bathroom is in the bedroom. But anyhow, it condensates and I need to know what I can do to it to stop that condensation.

TOM: So the vent in the bathroom is getting the condensation when it’s cold outside. Can you get to the attic above it?

BOBBY: Yes. Yes, sir.

TOM: What I would do is I would insulate the exhaust duct for the bath fan. Because if you insulate that exhaust duct, then the warm – the air that’s inside of it will stay warm; it will not condense against the cold exterior. And that should stop the condensation issue from happening.

BOBBY: Mm-hmm. OK. Well, that’s what I needed to know. I appreciate it very much.

TOM: You’re welcome, Bobby. Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.