Bathroom Fan Venting In Attic

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

Bathroom fan venting in attic. Through the roof or an exterior gable wall. 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. 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.

Use rigid metal ducting aluminum or galvanized steel with lengthwise seams facing up and joints sealed with foil tape or duct mastic or rigid plastic pipe. If your attic is enclosed california s building code states it should have cross ventilation. Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems. It seems like such an easy solution just leave a bathroom vent hose in an attic.

However you can vent a bathroom fan through an attic while it terminates on the roof or gable end. That is openings doors windows and louvers to the outside should create a. See bathroom vent duct termination for details about how to terminate the bath exhaust vent duct. It can be an ugly sight to crawl above a poorly ventilated bathroom s ceiling.

Exhausting of the bath vent fan must indeed be to the building exterior. Improperly ending a bathroom vent inside an attic can lead to unintended consequences and builders have stopped this bad practice many years ago. You should never exhaust the bathroom fan directly into the 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.

Venting fans pull moisture laden air out of that small space slowing or altogether preventing it from condensing on walls on the ceiling or worst of all in the ceiling. No you cannot vent your bathroom exhaust fan into the attic. This involves running ductwork from the fan usually though an attic and out through the roof. 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 s all outdoor air anyways right. No you should not vent a bathroom fan directly into an attic. Example model ventilation codes. Exhaust air from toilet rooms and bathrooms shall not discharge into attic crawl space or other areas inside building.

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.