Bathroom Vent Exhaust Into Attic

Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems.

Bathroom vent exhaust into attic. Through the roof or an exterior gable wall. You can find 4 in. 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.

Duct already wrapped in insulation at home centers. Each fan vents separately out the roof. In order to accomplish this the roof has to have a hole cut in it. So you do need to get that vented outside whether it s through the siding with one of those trap doors that sort of opens out every time you ve got it on or through the soffit.

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. Each bathroom has its own exhaust fan. However you can vent a bathroom fan through an attic while it terminates on the roof or gable end. You should never exhaust the bathroom fan directly into the attic.

This involves running ductwork from the fan usually though an attic and out through the roof. It may also violate a shingle warranty. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. Both bathrooms are vented by a single in line fan that has one exhaust vent running through the roof.

Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Because what happens is when the insulation gets moist from all that moisture that s being dumped into the attic it completely cuts down on the r value of the insulation. Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons. One in line centrifugal fan can be mounted in the attic to exhaust the moisture from two bathrooms.

Although this isn t always possible in attic crawl spaces you should always insulate the duct to prevent condensation problems. 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. 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 is because of this that many builders tend to advise against this method.