Bathroom Vented Into Attic

It cannot move air to a crawlspace or attic.

Bathroom vented into attic.

Each bathroom has its own exhaust fan. 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. Each fan vents separately out the roof. An enclosed toilet would require its own exhaust fan exhaust fans approved for installation in wet areas would need to be located over or near the shower or tub bathroom doors should have at clearance to the floor.

It is because of this that many builders tend to advise against this method. Exhausting of the bath vent fan must indeed be to the building exterior. This involves running ductwork from the fan usually though an attic and out through the roof. The bath should be vented by either a 20 cfm continuous vent fan or a 50 cfm vent fan that is intermittent or switched.

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. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. 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. It may also violate a shingle warranty.

Exhaust air from toilet rooms and bathrooms shall not discharge into attic crawl space or other areas inside building. Bathroom exhaust fans perform an important function by removing excess moisture from your home. Mold growth wood rot and structural deterioration moist bathroom air is sucked back into the home interior excess moisture attracting rodents and pests. While this may seem obvious homeowners may out of convenience direct the vent into either of these locations.

There are several other factors to consider for proper ventilation such as. One in line centrifugal fan can be mounted in the attic to exhaust the moisture from two bathrooms. Both bathrooms are vented by a single in line fan that has one exhaust vent running through the roof. However there are a few real potential downsides when a bathroom vent is improperly terminated inside an attic.