Venting Bathroom Fan Through Existing Roof Vent

In this video this old house general contractor tom silva shows how to properly install a roof mounted bath fan vent.

Venting bathroom fan through existing roof vent.

From inside the attic drive a nail through the roof directly above the bathroom vent fan. Options for venting a bathroom exhaust fan include best to worst. Center the nail between two rafters. Sometimes this is preferable to do so that the roof doesn t need to be disturbed and then at a later date when replacing the roof a proper vent is added.

In order to accomplish this the roof has to have a hole cut in it. Bathrooms are wet smelly places that often are closed in and unventilated. If you re tempted to vent your exhaust fan through an existing roof vent or even vent it into the attic don t do it. 25 or 50 cfm ft for hotels motels resorts and dormitories and a slightly more modest 20 50 cfm for private dwellings.

Through the roof depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. Moisture though is the real problem since it can create potentially hazardous mold and mildew eating away at your walls ceiling and trim. But you can install one fan in your attic for both bathrooms and make your bathroom quieter too. By the diy experts of the family handyman magazine one fan two vents.

Second during cold winters you ll be blowing warm moist air onto a cold surface the roof vent and roof plywood. However it is possible to use the existing roof vent often the duct is secured to one side of the roof vent so that it can still be used for attic ventilation. From the roof find the nail and use the utility knife to cut roof shingles from around the nail. Required bathroom vent fan ventilation rate in cfm.

Ideally your fan should be near the tub or shower but not right next to an air conditioning heating vent as the forced air can create currents that disrupt the bathroom fan s steady intake of. This ventilation code specifies a bathroom exhaust airflow rate for toilet rooms and bathrooms not served by a window of adequate size of. Bathrooms can only benefit from some type of exhaust venting system but which type do you need and what does the bathroom exhaust fan venting. Bathroom exhaust fans perform an important function by removing excess moisture from your home.

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. This involves running ductwork from the fan usually though an attic and out through the roof.