Bathroom Exhaust Fans Into Attic

Duct already wrapped in insulation at home centers.

Bathroom exhaust fans into attic.

Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons. One attic mounted fan for two bathrooms 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. Mold is commonly found in attics with bath fans that exhaust moist air into the attic.

The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. Although this isn t always possible in attic crawl spaces you should always insulate the duct to prevent condensation problems. Ideally your fan should be near the tub or shower but not right next to an air conditioning heating vent as the forced air can create currents that disrupt the bathroom fan s steady intake of. 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.

Mold can spread rapidly in an 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. You can find 4 in. No you cannot vent your bathroom exhaust fan into the attic.

It s all outdoor air anyways right. Bath fans should always exhaust outside through the roof via insulated duct and terminate on a dampered roof cap. For instance if your home has an attic you can get to the fan from above. 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.

It may also violate a shingle warranty. However you can vent a bathroom fan through an attic while it terminates on the roof or gable end. Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems. Bathroom exhaust fans perform an important function by removing excess moisture from your home.

Click here to learn more about attic mold. When you replace a bathroom fan in a home with an attic the job will usually be a lot easier. If you have two bathrooms that are close together and one has an exhaust fan and the other doesn t you might be wondering if you can tie a new exhaust duct into the existing one. Proper bath fan exhaust.