My master bathroom is wired for a fan, but I opened it up and found that it is just venting into the joist between the ceiling and the second floor.
There are no exterior walls to access in the bathroom. Also the joist runs to the main house in one direction, and to a back room in the other.
The back room has the end of a hip roof over it, but I don't think there is any access into the roof section.
So I think the only option would be to bring a vent down the joist, through the wall into ceiling of the back room and out through the roof. Is something like this possible without completely cutting up the ceilings and the roof?
I'll probably have a pro look at it, but how much would something like this cost?