Cutting exhaust fan hole in roof. Suggestions?

[Bismarck Jack]

Tonight i will finish the taping in the bathroom, but I would like to get the exhaust fan vented outside. Ranch style home, and this bathroom is on the main floor, so the roof is a straight shot, about 4 feet from the exhaust vent/fan itself, which is already in and wired.

My questions are: what is the best way to go about cutting the circle for the 4 inch duct work to connect to the exterior vent housing. Do i just sawsall a circle right through the shingles, or should carefully take off the shingles around the spot i will cut the hole first. where is the best spot, closer to the top of the roof or the base? I bought one of those kits, so there shouldnt be much guess work. I just dont want water getting in after i cut that hole in the roof.

what is the best way to attack this thing?:fight:

[pushkins]

It makes little difference in the scheme of things high or low for the venting. I've head arguements that it is better high because of a better air flow to help "draw" the air and the flipside arguement about more wind and cold air to drop in on down the vent line. The simple goal is to push the moist air out the vent as soon and as easily as possible without allowing it to condense back to water and then lead to all sorts of problems.
My best advice is that the vent line should be as straight and as direct to the roof vent as possible.

As for cutting the hole, I always cut straight through the shingles, carefully remove the shingle sections and then cut out about 1/4" extra from the round cut hole, this gives you plenty of room when you put them back down after installing the vent hood.

Easy way to cut the hole, put a long screw up throught the roof from inside the attic space, then get yourself a small piece of flat wood drill a hole in one end, measure out 2" from this hole and drill another hole big enough to put a nail through (2" radius is assuming a 4" roof vent) on the roof put the first hole over the screw that you drove in from the attic and use the other hole as your scribe to mark the shingles. (you probably already know that). Then just cut it out with your jigsaw.

[Bismarck Jack]

Ok, Great!

I will use the scribe idea since i dont have a battery powered jig or sawsall. It will be easier to put an extension from the bathroom window up on the roof.

Once this is done, I just need to get that black tar goo and goo the crap out of it?

Also, Can a guy place insulation right over the top of these fans?

thanks for the help