The steps for installing a ridge vent include removing the cap shingles, installing the ridge vent kit and replacing the cap shingles. The process also involves cutting a slot into the wood sheathing.
To remove the cap shingles and prepare the roof for ridge vent installation, use the claw end of a hammer to pry away the cap shingles at the edge of the roof. Use a chalk line to snap the center of the ridge peak, and then snap the lines parallel to that peak. Use a pencil to mark slots 6 inches from the inside corner of the end wall. Measure out the length of the ridge vent hole, and then mark slots 6 inches beyond again, Repeat this process the entire length of the roof so that the ridge vents are installed at 6-inch intervals.
Set a power saw to a 3/4-inch depth. Use the saw to cut along the chalk line running parallel to the peak. This creates the slot for the vent. Remove the debris.
Follow the instructions that come with the ridge vent kit. Insert an end plug, and fasten that section to the roof line. Use 2-inch roofing nails. Continue nailing sections of ridge vent to the underside of the roof, making sure to align it with the slot cut out of the wood sheathing. Cover the end with an end plug. Place the metal ridge vent covers over the slots, securing with the roofing nails.
If possible, re-use the removed cap shingles. Otherwise, cut new shingles and secure them with 2-inch roofing nails. Use the roofing nails to secure straps over the joints in the vent.