Bathroom Fan Vent Through Attic

Improperly ending a bathroom vent inside an attic can lead to unintended consequences and builders have stopped this bad practice many years ago.

Bathroom fan vent through attic.

Options for venting a bathroom exhaust fan include best to worst. 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. You can find 4 in. It is because of this that many builders tend to advise against this method.

Each fan vents separately out the roof. However you can vent a bathroom fan through an attic while it terminates on the roof or gable end. In all cases the ducting needs to conduct the exhaust to the building exterior and needs to terminate in an animal proof vent cover. Up through roof down through floor or crawl area.

One in line centrifugal fan can be mounted in the attic to exhaust the moisture from two bathrooms. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. Let me tell you. The building code requires a bathroom exhaust fan to vent outside the building so installation of a new bathroom fan necessarily involves installation of ductwork.

This involves running ductwork from the fan usually though an attic and out through the roof. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Bath vent fan duct routing. 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. Surprisingly bathroom fans are not required by some building codes. This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space. This is much easier to do if you have attic access because if you don t you usually have to remove some ceiling drywall and run the ducts along a joist.

In order to accomplish this the roof has to have a hole cut in it. Although this isn t always possible in attic crawl spaces you should always insulate the duct to prevent condensation 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.

It s all outdoor air anyways right. Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside. Each bathroom has its own exhaust fan. No you cannot vent your bathroom exhaust fan into the attic.

Both bathrooms are vented by a single in line fan that has one exhaust vent running through the roof.