# Venting Bathroom Fan through Flat Roof



## bluefitness (Sep 4, 2008)

stubits said:


> The way our house is constructed the only option to vent the bathroom outside is through a modified bitumen flat roof. Is there a specific type of vent that can be used? Does something like this work, or is there something better?
> 
> http://www.hvacquick.com/hqthconfig.php?fm=GJ



I would try to vent it through the side wall if you can. If you insist on going through the roof, I would ask this question in the roofing section. They will have better knowledge of sealing roofing penetrations.


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## Plumber101 (Feb 25, 2009)

The link here will be better because it provide a flap seal that will close when the dryer is not being used.


http://www.iaqsource.com/product.php?p=american-aldes_22-041&product=174479


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## stubits (Dec 30, 2008)

Thanks everyone!I have no choice but to vent through the roof. I know how to seal it on the roof, but was curious as to the best type of vent to use.Thanks for the suggestion, but I am trying to vent a bathroom fan, not a dryer.Any further suggestions?Thanks!


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## Plumber101 (Feb 25, 2009)

You can still use the vent cap that I suggested to you for a bath exhaust fan. You just want a vant cap that closes when not in use so that outside air will not back feed.

I use dryer vents to vent bath exhaust fans all the time.


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## evapman (Mar 25, 2007)

Agree with plumber101, only thing I wonder is where are you located? If in snow country I would have to suggest going thru with a roof jack and extending a insulated pipe above the snow line and then a vent cap with dampers. That way it won't get covered with snow and not vent correctly. ( don't ask how I know this).  just my .02 worth


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## stubits (Dec 30, 2008)

Thanks guys, that actually looks like a great vent, just wasn't sure it worked for a bathroom vent. Great to know it will work.Snow is a good question. We don't get much, a few inches at most at a time. How much snow counts here? Oh, and what is a roof jack?


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## Plumber101 (Feb 25, 2009)

If you only get a few inches then this cap shouldn't be a problem. You can build a riser for this cap and raise it if you need to.

Most roof jacks are for round pipe. Just google roof jack to see a pic.


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## evapman (Mar 25, 2007)

stubits said:


> Thanks guys, that actually looks like a great vent, just wasn't sure it worked for a bathroom vent. Great to know it will work.Snow is a good question. We don't get much, a few inches at most at a time. How much snow counts here? Oh, and what is a roof jack?


Maybe roof jack is not the correct word, flashing maybe better word like the rubber kind you cut to fit around the size pipe used(as in Dektite pipe flashing). Old words for me I'm old! lol Well amount of snow is if the vent is down on roof surface would be enough to compleatly cover it either on the level or drifting.Prolly not a problem tho if not much snow there. :thumbsup:


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## stubits (Dec 30, 2008)

Thanks guys! This is perfect.


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