How necessary, really, is a bathroom exhaust fan? I've just ripped my combination fan/light out, and I'm trying to decide what to do next.

I removed the existing fan largely because it was venting directly into the attic. I have serious problems with ice-dams on that quadrant of my roof. My thinking is that perhaps the fan venting warm air into that area is heating up my roof, causing the snow on that part of the roof to melt just enough to form the ice. It's a theory, anyway, and I've decided to test it by stopping the ventilation into the attic, which I've done.

I now have this 8 1/2 x 8 1/4 square hole in my bathroom ceiling. For now, I've just blocked it up so hot air doesn't escape into the attic. In the long run though, I need to either put in a light or put in another combination light+fan.

So far as I can tell, the home, built in the early 1950s, originally did not have a bathroom fan. The combination fan+light that I just removed is pretty clearly a retrofit. Thus, if no fan was necessary when the home was built, it's hard for me to comprehend why one is necessary now.

Thoughts? It'd be easier to just put in a regular light fixture. If I need a fan, then I need to somehow vent it to the outside, and that's probably a fair bit more work.


Jonathan Gennick
http://gennick.com

ice-dams and soffit insulation