Bathroom Vent Pipe In Attic

Each fan vents separately out the roof.

Bathroom vent pipe in attic. It may also violate a shingle warranty. 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. Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside. A cold duct allows condensation of moist indoor air leading to drips from the exhaust fan.

Condensation can be a problem in an uninsulated attic so the homeowners trades resource center recommends installing rigid pipe with a minimum slope of 1 8 inch per foot toward the vent outlet to keep water away from the fan. You can find 4 in. In some localities the building department may require the use of r 3 to r 8 fiberglass pipe insulation to control condensation and even when it isn t required it s a good idea to use it especially if the vent opening is likely to ice up during the winter. You should never exhaust the bathroom fan directly into the attic.

The reason exhaust pipes are insulated in unconditioned spaces your attic is because they carry warm and moist air from your home to outside. Each bathroom has its own exhaust fan. Is there any particular type of piping to be used through the attic metal ductwork pvc etc. Exhausting of the bath vent fan must indeed be to the building exterior.

If this pipe is not insulated the heat carried in the air transferred to the pipe will cause condensation and potentially cause water damage at your ceiling or in your attic. 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. Although this isn t always possible in attic crawl spaces you should always insulate the duct to prevent condensation problems. One in line centrifugal fan can be mounted in the attic to exhaust the moisture from two bathrooms.

Otherwise the exhaust duct gets too cold when it runs through the attic. See bathroom vent duct termination for details about how to terminate the bath exhaust vent duct. Does bathroom vent piping need to be insulated. Example model ventilation codes.

Exhaust air from toilet rooms and bathrooms shall not discharge into attic crawl space or other areas inside building. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. Bathroom exhaust fans perform an important function by removing excess moisture from your home.