Bathroom Vent Discharge Into 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.

Bathroom vent discharge into attic.

Through the roof or an exterior gable wall. Health and structural issues when a bathroom is not vented properly. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Each bathroom has its own exhaust fan.

Rusted fixtures condensation from moisture laden air can cause health and structural problems as well especially when the bathroom vents discharge moist air into attics or crawl spaces. Leaking and damaged vents as well as improperly installed ones also can cause problems. It may also violate a shingle warranty. That will take it from the bath exhaust fan to a discharge point.

Exhausting of the bath vent fan must indeed be to the building exterior. Allowing the exhaust to vent into your attic can potentially cause several moisture problems. M1507 2 exhaust air from bathrooms and toilet rooms shall not discharge into an attic crawl space or other areas inside the building. No you cannot vent your bathroom exhaust fan into the attic.

The next thing you need to do is make sure the exhaust is successfully making its way out of your home. Now where the discharge point is is going to be up to you. It is because of this that many builders tend to advise against this method. The bath should be vented by either a 20 cfm continuous vent fan or a 50 cfm vent fan that is intermittent or switched.

Both bathrooms are vented by a single in line fan that has one exhaust vent running through the roof. Options for venting a bathroom exhaust fan include best to worst. M1501 1 air shall not be exhausted into an attic soffit ridge vent or crawl space. This involves running ductwork from the fan usually though an attic and out through the roof.

A lot of options. Sizing a bathroom fan can be somewhat tricky as the information out there is all over the place. Each fan vents separately out the roof. The exhaust needs to vent outdoors.

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. Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside. If you re simply replacing the fan the ducts should already be set up for you.

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.