Bath Fan Vents Into Attic

If you re tempted to vent your exhaust fan through an existing roof vent or even vent it into the attic don t do it.

Bath fan vents into attic.

Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems. Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons. The exhaust vent must terminate outdoors. It s all outdoor air anyways right.

You should never exhaust the bathroom fan directly into the attic. However you can vent a bathroom fan through an attic while it terminates on the roof or gable end. Options for venting a bathroom exhaust fan include best to worst. It seems like such an easy solution just leave a bathroom vent hose in an attic.

Through the roof or an exterior gable wall. First you ll partially block your roof vent with the piping reducing the flow of cooling air through your attic. Do not simply terminate a bath vent fan duct in an attic as shown in our photo above nor can you just dump the exhaust vent into a crawl space nor into a closed wall floor or ceiling cavity. When venting a bathroom exhaust fan make sure to vent the air to the outside rather than into your attic where it can cause mold and mildew to form.

Second during cold winters you ll be blowing warm moist air onto a cold surface the roof vent and roof plywood. No you should not vent a bathroom fan directly into an attic.