How To Vent Bathroom Fan Through Attic

Options for venting a bathroom exhaust fan include best to worst.

How to vent bathroom fan through attic.

If you vent through a soffit where attic vents are often located the moisture will get sucked back up into the attic or roof venting. Through the roof or an exterior gable wall. The best way to do it is to give the bathroom exhaust fan its own direct vent to the outside of your home and not into the attic where it can mix with the air causing the issues mentioned above. The correct way to vent a bathroom fan through an attic is to terminate the vent either to the roof or to the gable wall.

If you are using flexible fan duct stretch the flexduct tight to keep it as straight and smooth inside as possible. Long sloppy bending flexduct runs significantly reduce the performance of the vent fan. A single exhaust exits through the roof figure a. 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.

Flex duct routing details. 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. A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan. Because the fan is in the attic you ll hardly hear it.

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. In attic seal holes in fan housing with foil duct tape. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. This involves running ductwork from the fan usually though an attic and out through the roof.

Since you cannot vent a bathroom exhaust fan into the attic what are your options. Use foil duct tape to attach flexible duct to connector protruding from the wall cap. You mount a switch in each bathroom. Connect the flexduct to the fan itself using plastic ties or second best duct tape.

This system is quiet too. In order to accomplish this the roof has to have a hole cut in it. It is because of this that many builders tend to advise against this method.