Seal Gap Around Bathroom Exhaust Fan

On occasion a home improvement enthusiast may discover that the opening cut in the drywall to install a bath fan is not completely covered by the fan s.

Seal gap around bathroom exhaust fan.

There will be residual caulk if the bead is cut but the bead is hidden under the fan grill. Venting a bath fan into an open attic is a recipe for rot mold and other issues. Cut an access in the box for the exhaust duct. Similar to a dryer exhaust bath fans should vent outside.

Fully insulated bath exhaust fan image courtesy of the doe summary. Air seal around kitchen and bathroom exhaust fans to keep conditioned air from leaking into unconditioned space. Bath exhaust fan with rigid foam box image courtesy of the doe 3. One great and inexpensive addition is a simple timer switch.

I ve got my exhaust fan installed in the ceiling of the bathroom now i m wonder how best to seal the gap around it. Cover the box with attic insulation. I use the minimum amount of caulk to fill the gap and seal the housing to the drywall. Before entering the shower set the timer switch for about ten or 15 minutes longer than you ll be in the shower.

Which isn t to say you couldn t use rope caulk instead of tube caulk. Seal the box to the ceiling gypsum board and seal around the exhaust duct with caulk or canned spray foam. The fan housing is obviously sheet metal and the ceiling has the plastic vapor barrier on top of the drywall.