Bathroom roof vent for a flat roof
I’ve had a chronic problem with a leaking bathroom vent during storms (like this one). I thought I fixed it last month when I found some exposed flashing around the vent on the roof. Apparently not. I think now that the vent shroud was intended for a pitched, not flat roof. It appears that this…
I’ve had a chronic problem with a leaking bathroom vent during storms (like this one). I thought I fixed it last month when I found some exposed flashing around the vent on the roof. Apparently not. I think now that the vent shroud was intended for a pitched, not flat roof. It appears that this vent was intended to have its opening pointing “downhill”, which of course it can’t with a flat roof.
What kind of vent should I have? Is there a name for it?
Thanks, Denton. I’m looking just for the vent. Lowes and HD carry powered mushroom vent fans too, as I learned on my quest this afternoon. That’s probably what I should have installed initially because they’re more powerful.
Incidentally, I blogged about this:
http://www.brooklynrowhouse.com/life_sucks_and_then_you_renovate
Steve, if you’re looking for a mushroom _fan_ not just a passive vent, they are readily available from Grainger. Loren Cook is a big mfgr., as is Dayton.
The flashing around the vents was poorly done but I fixed that last fall with tar and roofing fabric, hoping that I fixed the leak as well. No such luck. It turns out that the (idiot) contractor’s helper who installed this vent shroud used one that’s intended for a pitched roof. It’s a flat box, about 4″ high, with one side open. The way it’s configured, it works so long as there’s no driving rain coming from the north and no heavy snow melt next to it.
I found what I need. It’s called a “roof jack” or “mushroom vent”. That’s the only kind of vent that should be installed on a flat roof. I drove all over today looking for one… Lowes, HD, Doody’s… no luck. I found one online:
http://www.hvacquick.com/hqthconfig.php?fm=GJ
I just need to pull the fan and see what size ducting it’s got (probably 4″).
Do you have a picture of the vent? From your description, It’s hard to tell if the water is coming into the vent itself, or the flashing around the vent.
We had a bathroom exhaust fan installed in our top floor bathroom several months ago–we had to coordinate an electrician and a roofer. The vent the roofer installed is a couple of feet tall and has a cap on it. It sounds like you might have one of the small caps that is intended for a through-the-wall vent which, as you now know, won’t keep the rain out. Any good roofer should be able to install a proper vent, designed for a flat roof.
Sorry, I was obtuse. This is for a bathroom exhaust fan vent not a plumbing vent.
I do not have a shroud around my vent at all, just tar sealing the roof to the vent stack.