Need advice for bathroom exhaust fan on roof

Old 06-14-24, 02:20 PM
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Need advice for bathroom exhaust fan on roof

I am installing a fan in the bathroom, What kind of vent should I have on the roof? Should it have a flapper? I would think a flapper could freeze shut from the moisture.
Old 06-14-24, 02:27 PM
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They should always have a damper.
Old 06-14-24, 03:55 PM
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If you can vent sideways out a wall, it would be less problematic viz leaks. It's worth a little effort to do so. Sidewall terminations for bath and dryer vents often have spring loaded louvers.

Search "building code bath vent <your city or county>" for more info about materials, location, etc. Different areas adapt codes at different times and occasionally add their own twists - so if you can find what your own location uses, you're ahead of the game.

Although many people complain about codes messing up their life when they have cheap creative ideas, in my experience most of the "code" out there is based on sound logic and is really worth checking.

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Old 06-14-24, 04:38 PM
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Unfortunately when installing an exhaust fan in the second floor bathroom.... the ceiling is above the wall. Too high to install a side wall vent. That leaves the roof as the best location.
Old 06-14-24, 06:32 PM
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That would be a problem for a fan in the ceiling. If you can consider a fan in the outside wall, maybe not so much an issue. Lots to consider, not least of which is who is doing the work - because tradesmen hate new/unusual situations, and with good reason. Predictability and same ol' same ol' is what makes the money.

I can recall one fan I put in the wall and there was no particular problem. I just wish I'd popped for the most expensive one instead of low-mid. Size was same but noise level would (IIRC) be much better. Install was straight forward in a 2x4 exterior wall. If you do consider the option, note the termination, hood or whatever shows on the outside and be sure you're good with that. Also, maybe don't install too low above a tub which uses a shower curtain - damn things suck in even when the fan is in the ceiling. The one I installed was 18" above the rod due to the old house having 9' ceilings; my tenants haven't complained in the 20 years it's been in use but not sure that says much...

Old 06-20-24, 10:16 AM
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Weekend project to install 2 of these in the roof for bathroom vents.

I'd rather vent out the wall if possible, for leak potential and snow covering, but sometimes it's just not possible.

Though you didn't ask, my preference is Delta Breeze fans for lower-cost and Panasonic if you're willing to spend a bit more. Whatever you buy, look at the sone level and get one either 1 sone or less. Some of the major brands have 3-4 sone fans and I don't understand why anyone would want that much noise.


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