Bathroom Vent Fan Venting Into Attic

The exhaust vent must terminate outdoors.

Bathroom vent fan venting into attic. 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. All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans. Through the roof or an exterior gable wall. It seems like such an easy solution just leave a bathroom vent hose in an attic.

No you should not vent a bathroom fan directly into an attic. This involves running ductwork from the fan usually though an attic and out through the roof. Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside. It is because of this that many builders tend to advise against this method.

In order to accomplish this the roof has to have a hole cut in it. No you cannot vent your bathroom exhaust fan into the attic. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Surprisingly bathroom fans are not required by some building codes.

Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems. You should never exhaust the bathroom fan directly into the attic. Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside. 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.