How To Vent A Bath Fan Through The Roof This Old House

Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot.

How to vent a bath fan through the roof this old house. Here this old house general contractor tom silva shows the proper way to install a bath vent fan. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. From inside the attic drive a nail through the roof directly above the bathroom vent fan. In this video this old house general contractor tom silva shows how to properly install a roof mounted bath fan vent.

From the roof find the nail and use the utility knife to cut roof shingles from. This will serve as a reference point for positioning the wall cap. This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space. The master bathroom and the 2nd bathroom vent through the roof and through the same opening.

From outside use 4 inch hole saw to cut hole for wall cap. The 2 pipes one a 4 master and the other a 3 2nd do not go through the ceiling but into a common box that goes through the roof. Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out. Drive nail through house wall from attic.

Center the nail between two rafters. This involves running ductwork from the fan usually though an attic and out through the roof. Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof. In this video this old house general contractor tom silva explains how to vent a bathroom fan.

It eliminates the need for routing ductwork through the house and these fans usually dry the bathroom more quickly. Heath shows that most bath fans have the fan mounted right over the register but there is an option where the fan is located elsewhere often an attic or basement and is ducted to both the bathroom register and the vent to outside. The 2nd bathroom vent drips on the floor and is ruining the ceiling. If you vent through the roof condensation will drip back into the interior.

I recommend that my clients vent their bath fans out a gable wall if at all possible when not using an hrv or erv that is. Other venting options includes running the duct up through the roof or down through the soffit. Do not vent through a soffit. If you vent through a soffit where attic vents are often located the moisture will get sucked back up into the attic or roof venting.

In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover.