How to Install a Solar Attic Fan

Choose an installation location on the sunny side of your house near the middle of the attic space. From inside the attic, use your pencil to mark a spot midway between two rafters and 20 inches below your roof's ridge.

Drill a hole through the roof deck from inside the attic at that spot. Release the drill bit from the chuck, and leave it protruding through your roof .

Locate the drill bit protruding from the roof outside, and tie a string to it. Create a compass by tying the chalk to the string exactly 7 inches from the drill bit. Use the compass to draw a circle 14 inches in diameter.

Cut through the shingles along the chalk line using a utility knife. Remove shingles from inside the 14-inch circle while leaving the compass in place. Remove nails with the pry bar. Redraw the 14-inch diameter circle using the compass.

Cut out the 14-inch circle using the reciprocating saw. Trim a 2-inch arc from the shingles directly above the opening. Visualize the opening as a clock, and trim from 10:00 to 2:00. The result will be a 2-inch band of bare roof deck from 10:00 to 2:00.

Slide the attic fan into place by putting it over the opening and slipping the top edge of the integrated flashing under the shingles through the 2-inch arc. Don't force the flashing past an obstruction like a nail or staple. Instead, gently lift the shingles and remove obstructions with a pry bar or flathead screwdriver.

Lift the base of the fan from the bottom and apply a continuous bead of caulk around the hole, under the flashing. Apply a liberal amount of caulk at the top, 2 to 3 inches beyond where the flashing goes under the shingles.

Fasten the fan to the roof by driving roofing screws with gaskets through the flashing and the caulk bead using the drill with your hex driver attachment. Caulk over the screw heads.