They are kind of hard to describe, but basically what you want is a
galvanized roof cap for a bathroom fan. There is a picture of one here
http://media2.askthebuilder.com/askt...oads/546-1.jpg.
In my experience, go to a small hardware store, home depot only has
one or two kinds, and the small hardware may have several different
kinds that willl suit your application. Another option is to use a pvc
pipe and plumbing vent stack flashing, but the pvc pipe will need a
trap, or a J bend at the top to prevent water from coming back into the
fan.


JoeSpareBedroom wrote:
The previous owners of my home routed the flex duct from the bathroom fan
right to the underside of a normal roof vent and sort of wired it in place.
I'm about to re-roof the house, and although I'm tending away from this
idea, an acquaintance comes highly recommended for this kind of work. Three
person crew, all permanent people. But, while looking at the roof with him
today, he gave me a blank stare when I mentioned a vent specifically for
fans. Can anyone describe what these things look like?

Yes, I have two estimates from "real", insured companies. :-)