Install Bath Fan Vent On Metal Roof

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

Install bath fan vent on metal roof.

Leave the drill bit sticking through the roof so you can find the hole. Install the roof vent install the roof vent by sliding the top flange under the shingles above it and resting the bottom flange on the shingles below. We explain how to install bathroom exhaust fans or vents the vent ducting the vent termination at the wall soffit or roof vent fan wiring bath vent duct insulation bath vent lengths clearances routing and we answer just about any other bathroom ventilation design or installation question you may have. Center the nail between two rafters.

From inside the attic drive a nail through the roof directly above the bathroom vent fan. Also this is the section of roof that gets hit directly with heavy winter winds. Secure the vent flanges with roofing nails before installing the shingles. For optimum performance locate it between the shower and the toilet.

Try to keep it close to the fan location. From the roof find the nail and use the utility knife to cut roof shingles from around the nail. Various size vents will come with recommendations regarding spacing and placement based on the size of the vents and the expanse of the roof. Apply roofing adhesive on the underside of the flanges to seal.

Climb into the attic and clear away any insulation from around the hole. This will involve determining the placement of the vents. Prepare the roof area. Start in the attic and drill a hole through the roof in the desired vent location.

Use rigid metal ducting aluminum or galvanized steel with lengthwise seams facing up and joints sealed with foil tape or duct mastic or rigid plastic pipe. 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. From up on the roof use a jigsaw or reciprocating saw to cut a 4 in. Fwiw here is a url to the photo of the roof.

The internal construction of the house does not permit me to vent the bathroom fan elsewhere. Draw a mark on the bathroom ceiling where you d like to install the vent fan.