Bathroom Exhaust Duct In Attic

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.

Bathroom exhaust duct in 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. There we also note. We explain at bathroom ventilation codes specs installers should make the bath vent fan duct run through the attic or any other space as short as possible. Bathroom exhaust fans perform an important function by removing excess moisture from your home.

It may also violate a shingle warranty. 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 is because of this that many builders tend to advise against this method. Wall mount fans are mounted on an external wall of a home and are used if there isn t a way to vent through the roof as in the case of a bathroom on the first floor of a home.

Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. 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. Bathroom vent fans are rated by how many cubic feet of air they can move in one minute known as the cfm rating. Ceiling fans vent either into the attic or outside through the roof.

In order to accomplish this the roof has to have a hole cut in it. Bathroom fan sound levels. To determine which size fan to buy for your bath multiply the room s square footage by 1 1. The bathroom here is below an accessible attic so tom ran the exhaust duct across the attic and out a gable end.