View Full Version : bath fan exhaust

02-24-2007, 05:46 PM
I just gutted our main bath a couple of days ago, rebuilding slowly now. I am installing a light / fan combo in the center of the small room and direct venting with a 4" flexible wire clad hose to what I would consider a non-vented soffit that has been covered with 12" center vent vinyl soffit material. Here is my trouble .... I cut a 4" hole in the wood soffit, secured the hose with a couple roofing nails, then when I buttoned the soffit back up, the venting holes didn't line up with where I ( sorta aimlessly ) cut my hole. :mad:

Should I ...

a) cut a new hole, and patch the old so it lines up

b) drill some small holes in the existing location

c) install a flapper vent cover like for a dryer ( trouble with this option is the flaps would never close as it will be hanging on the horizontal of the soffit )

d) leave it alone set my tub, toilet, tile and call it good :)

thanks in advance, and if pic's are needed for clarification, I can shoot some tomorrow.

02-24-2007, 08:07 PM
Are you saying the wood soffit is cover by vinyl, and you're dumping he exhaust in between? No good, especially in our climate. (I moved from Vestal in '83.)

There are vents designed for mounting in the soffit. Get the right product for the application. You can probably go through the hole you already cut and then throuh the vinyl, but follow the installation instructions on the soffit vent.

02-25-2007, 09:28 AM
Yes, guess I am saying that, though the vinyl material is nailed directly to the wood, the only gap there is what is created by the profile of the vinyl .... maybe 1/2" or so.

Since we won't be using the room for a while yet, this will give me some time to research the right item.

I do a lot of business in Vestal, many new homes built over there.

Thanks for the reply !:)

02-26-2007, 06:18 AM
The hole you cut in the (covered up) plywood is meaningless, you can just abandon it w/o patching. Use a hole saw (probably 4.5 inch, but check vent instructions) to cut from the outside, locating it where best for appearance & function. You may want to use a metal elbow to make the turn down to the vent. With the plywood backer, you should not have a problem drilling through from the outside. Use insulated flexible duct or insulate what you do use.

Be prepared to shim between the two soffits to prevent the vinyl from collapsing as you screw the vent in place. Depending on condition/thickness of the wood soffit, you may also need to back it up to give the screws something solid to go into.

Cut a pair of plywood (3/8, 7/16/, 1/2, sepending on space between old/new soffits) scraps 7x7 and use the hole saw to drill through them while standing on the ground, then use them (if needed) to build the "sandwich". The piece for between the soffits will need to be cut in 2 to fit through the 4.5 inch hole. No prob, it's just a shim.

02-26-2007, 03:50 PM
yes Ted, that seems like a good approach. Wifey is already in he know about this extra hole in the soffit so that will be on her 10 most wanted things to be done list until it's patched. I believe the cutout is still around, I'll prolly just caulk it back in with some PL if I need to move the hole that is. Buried with work, haven't had time to go to the local roofing / siding wharehouse for a part yet. Lone Depot didn't have anything I wanted.

There's plenty of 3/8, 1/2, and 5/8 ply scraps around from various flooring gigs of mine, so execution of your detailed plan should be easy. ;)

Thanks again, I am truly appreciative :)