Bathroom Fan Vent Exhausts Into Attic

It may also violate a shingle warranty.

Bathroom fan vent exhausts into attic.

Surprisingly bathroom fans are not required by some building codes. This involves running ductwork from the fan usually though an attic and out through the roof. Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot. Two bathrooms one roof vent both bathrooms are vented by a single in line fan that has one exhaust vent running through the roof.

It is because of this that many builders tend to advise against this method. 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. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. One in line centrifugal fan can be mounted in the attic to exhaust the moisture from two bathrooms.

No you should not vent a bathroom fan directly into an attic. Dumping bathroom exhaust into an attic or under roof space invites costly mold contamination frost under the roof in freezing climates moisture damage to roof sheathing possibly even plywood delamination or rot roof failures and shorter roof shingle life. Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside. In order to accomplish this the roof has to have a hole cut in it.

Vent your bath and kitchen exhaust fans through the roof through a special roof hood. However you can vent a bathroom fan through an attic while it terminates on the roof or gable end. All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans. It s all outdoor air anyways right.

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 seems like such an easy solution just leave a bathroom vent hose in an attic. Bathroom exhaust fans perform an important function by removing excess moisture from your home.