Roof-mounted fans are set into the roof of your house and will require you to cut into the roof during installation. You’ll then need to feel comfortable shingling around the fan area, though the installation process itself is relatively easy. Wall-mounted fans are meant to fit into a gable wall and for extra ease can be installed in place of an existing gable vent, which means you won’t have to remove any shingles or make significant changes to your attic. Keep in mind that fans are different, and there are no universal directions concerning the installation process. Follow specific directions indicated on your box.
Start by removing the shingles of the roof somewhere near the peak where you’re planning to install the fan. Cut an opening and install the fan over the opening. Re-shingle around the base of the fan. Contact an electrician to finish wiring the fan to a thermostat and make sure the electrical work meets code for your house.
Decide which gable to replace with a fan and make sure the fan you’re buying is approximately the same size or larger. Use a piece of plywood to mount the fan by selecting a piece of plywood of the right size, cutting an opening in the plywood, centering the fan over the opening and mounting the fan brackets to the plywood. Be sure to center the opening you cut in the plywood for the fan over the opening in the attic wall. Mount the plywood and fan to the attic wall. Contact an electrician to finish wiring the fan to a thermostat and make sure the electrical work meets code for your house.
Remove all cap shingles. Starting 6 inches from the end of the roof, cut through any shingles about 1. 5 inches from the ridge, and use a power saw with a blade depth of about . 75 inches to cut through the wood sheathing and create an opening. Install the ridge vent according to the type of vent you’ve purchased: for a shingle-over ridge vent, pre fasten the first section and add others until you’ve covered the entire opening, and for metal ridge vents align the vent over the opening and fasten with 2 inch roof nails. Metal ridge vents will require straps over the joints that will also need to be fastened with roofing nails. Shingle-over ridge vents get a layer of shingles so the look of the roof is less interrupted. Cut the cap shingle to size and reattach.
Determine the placement of soffit vents that will be free of objects and other obstructions. Remove the insulation that creates a barrier between you and the site of installation. Use a power saw to cut an opening for each of the soffit vents. The opening should be just slightly smaller than the vents themselves. Discard the removed pieces of wall. Place the vents and use screws to attach them to the eaves, and caulk the edges to ensure a tight fit with no air leakage. Reapply the insulation, though if the insulation prevents airflow in through the soffit vents and out through the ridge vent, insert baffles.
