Air sealing a bathroom fan
dave_naff
| Posted in General Questions on
I’ve been working on sealing our attic floor / ceiling (vented attic, climate zone 4A – PNW). I was surprised to see all sorts of holes around the fan casing effectively creating air gaps between my conditioned space and the attic – see the photo. Any reason not to tape these? I assume foil tape is probably better here than Tescon Vana?
Thanks in advance!
Dave
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Replies
Dave,
Yes tape any penetrations - best done on the outside of the housing. Peel & stick membrane works too.
Rather than trying to make the housing air-tight, I now put the whole thing in a plywood box sealed to the drywall.
Wow - Malcom, this is a great idea. I know putting recessed cans in a box is a great solution, but for whatever reason it never occurred to me to do this with a bath fan. Definitely going to steal this one for the toolbox!
Are you doing this for both new construction & remodel situations? I guess you could still do it in a remodel, you might just have to cut out more drywall to get the box up there? Then you could seal / glue the backside of the new drywall, re-mud, and you're done?
Paul,
Yes, I do it with all fans now. It's actually a bit more involved than my brief description to Dave. I make the plywood box big enough that it holds the fan, the housing, and the connections to the duct are accessible, so if in the future you want to change fans you can do so in a few minutes. You do have to buy a larger grill cover though.
I like this idea a lot, thanks a bunch!