Installing Bathroom Exhaust Fan Through Roof

This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space.

Installing bathroom exhaust fan through roof.

Other venting options includes running the duct up through the roof or down through the soffit. Vent your bath and kitchen exhaust fans through the roof through a special roof hood. Here this old house general contractor tom silva shows the proper way to install a bath vent fan. The 2 pipes one a 4 master and the other a 3 2nd do not go through the ceiling but into a common box that goes through the roof.

The warm air will exhaust out the duct and enter back into the attic through the soffit vent or ridge vent. Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot. The 2nd bathroom vent drips on the floor and is ruining the ceiling. The master bathroom and the 2nd bathroom vent through the roof and through the same opening.

Small bath fans provide adequate bathroom ventilation for 79 sq ft. For bathroom over 100 sq ft use a large or exhaust fan to circulate the air. Avoid venting through a soffit vent or ridge vent. And under while medium bath fans work well for bathooms 70 to 100 sq ft.

Letting the fan exhaust into an open attic will cause moisture buildup on the underside of the roof. In this particular installation tom ran the exhaust duct into the attic and through a sidewall to the outdoors. Pass the opposite end of the duct through the hole in roof. We explain how to install bathroom exhaust fans or vents the vent ducting the vent termination at the wall soffit or roof vent fan wiring bath vent duct insulation bath vent lengths clearances routing and we answer just about any other bathroom ventilation design or installation question you may have.

In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover. The first step in figuring out how to install a bathroom fan is cutting a hole based on the size of the fan you need. If you have access to the attic the fan can vent either through a gable wall or roof. Take the end of the duct with the connector fitting and attach it to bath vent fan.

Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out. But you can install one fan in your attic for both bathrooms and make your bathroom quieter too. Bend over the tabs then nail the tabs to the roof. Venting two bathroom exhaust fans through one roof duct won t work sorry to say.

The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood.