Adding a bath fan takes two major steps. First, is installing the fan and a switch to control it. The next step is venting it outside. You don’t want it to vent into an attic space because the moisture in the air can cause mold or rot or numerous other problems. Don’t worry, it’s a fairly basic process, assuming you don’t mind getting on the roof!

1. First, I like to go into the attic above the roof vent and locate a good spot for the roof vent from the inside. Steer clear of rafters and other items that would interfere. Usually, I can find a spot directly above the fan. I like to drill a hole through the roof at the center of the spot I’ve picked out.

2. Drilling a hole through the roof helps me locate the exact spot from the top side. I head outside, taking all the safety precautions so I live to write about it… I can find the hole I drilled and the use a jig saw to cut out a 5″ hole centered on the spot.

3. Test fit the vent and cut the shingles so that the upper courses will over lap the flange and surround the vent like the picture. Once it will fit, you can put in in place and put a few galvanized roofing nails around the edges. Remember the upper nails will be under the shingles, while the bottom corners are nailed from the top.

4. Seal the vent with roofing cement around the edges, under the overlapping shingles, and on any exposed nail heads. Grab your tools and head back to the attic.

5. Now it’s just a matter of hooking up both ends of the hose that came with the roof vent kit. I secured both ends with the included plastic straps and then covered each with aluminum foil tape to prevent any leakage. (sort of like duct tape, except it’s really meant for sealing ducts and it seals much better)

-Peter