Bathroom Exhaust Fan Goes Into Attic

Draw a mark on the bathroom ceiling where you d like to install the vent fan.

Bathroom exhaust fan goes into attic.

Climb into the attic and clear away any insulation from around the hole. It seems like such an easy solution just leave a bathroom vent hose in an attic. This involves running ductwork from the fan usually though an attic and out through the roof. It cannot move air to a crawlspace or attic.

For optimum performance locate it between the shower and the toilet. While this may seem obvious homeowners may out of convenience direct the vent into either of these locations. 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.

No you should not vent a bathroom fan directly into an attic. However you can vent a bathroom fan through an attic while it terminates on the roof or gable end. No it s never a good idea to have any exhaust fan in your home dump all that hot moist air in your attic. This section notes that air exhausted from the bathroom must be sent outdoors not indoors to the same residence or indoors to any other dwelling unit.

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. It is because of this that many builders tend to advise against this method. Click here to learn more about attic mold. 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. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Several different ways you can move that hot air to the outside. It can cause you a lot of problems with mold and mildew forming on the underside of your rafters and decking as well as getting into your insulation.

Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside. No you cannot vent your bathroom exhaust fan into the attic. 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. You should never exhaust the bathroom fan directly into the attic.

It may also violate a shingle warranty. Use an extra long 3 8 inch diameter spade bit to bore a reference hole through the ceiling and into the attic.