Installing a bathroom exaust fan in a ceiling that has a flat roof over it.?

Question

I need to install a batroom vent. The ceiling is flat and right above it is the roof. Nit sure if it is 2x6 or 2x8 beams between the roof and ceiling. No crawl space or attic. I have NO idea how to or where to begin. Exaust fans do not have instructions that go in to detail for flat roofs. I am going to get a cheep fan only. No light or heater. My main concern is Ducting it properly so I do not have issues with cold and condisation. I live in cold winter area. Any ideas or help????

Answer 1

Install the fan in an exterior wall instead of the ceiling. Here's a link.

http://www.kitchensource.com/bathroom-fa...

Answer 2

Use single-wall galvanized pipe (whatever size the outlet of the fan is - don't reduce it), poke it through the roof, get a gallon of roof tar + a roof jack, and that should do it.  I like to put a thick coat of tar under the jack, then mush the jack into it, add a few screws, and use the rest of the tar to completely cover the jack.  Keep some paint thinner on hand - there is an irresistible force, not well-understood by science, that attracts roof tar to the human body.  Gloves are not a bad idea.  s***w a vent cap to the top of the pipe.

If you can avoid a roof penetration, that's the better way, but if you can't, you can't.

Also note that some fans require a 12" straight section before elbowing up.

Answer 3

you  need to install a vent that exits thru the wall.....

  most roof are built with 2x6  joists, however     it not  en ought  to hold a vent pipe....

  perhaps even a elc  extractor vent would work  for  u