I am going to install a bath fan, are there any tricks I need to be aware of?

Question

The fan is in a small bathroom with an attic above. I am worried about proper venting with outside by making sure that no moisture reaches the attic without creating potential draft.

Answer 1

A lot of amateur vent jobs end up with either mildew at the fan or mildew on the roof sheathing.
2 rules to follow:
1- seal everything
2- insulate everything
Use sheet metal screws on all joints then use aluminium foil tape over them. Insulate around the piping but do not seal up the insulation in plastic(no moisture will escape if pipe is sealed and if any does it will dry up if not sealed in plastic) make sure entire length is insulated With no exposed areas
Use a roof vent with a back-draft damper and as much metal pipe as possible with only a few feet of straight flex if needed. Cover the exhaust fan with vapour barrier use 6 mil plastic and seal all holes extremely well especially where exhaust pipe penetrates plastic then cover with insulation.

Answer 2

Certainly your already aware of potential issues. Is the bath by chance at an exterior wall?

So many pre-installed vent fans are not strictly vented to an exterior, but since you have an attic above, the fan should vent to a side wall if possible. Is that even possible, given that the house may not still be in the initial construction stages?

Obviously the fan is designed to remove moisture, as well as odors to some degree, but the moisture has to have a place to go.

Steven Wolf

Answer 3

you can vent directly into the attic without having to go thru the roof.no moisture will get in and there will be no draft. if you've never done this before start with plenty of time ahead of you to complete the job. wear safety glasses to keep dust & trash out of your eyes. don't use power tools unless you just have to. take your time, don't get in a hurry, and be patient. it's not that hard to do.

Answer 4

turn off the power first...