Metal roof panels are available in a wide variety of colors and are a durable alternative to asphalt or clay shingle roofs. The metal panels come in standard sizes that are simply installed over each other on the existing roof. The edges of the metal panels overlap each other, which not only holds them in place but also prevents water from accessing the underlying roof wood. Tight seals at the overlapping points are critical to the long-term performance of the roof.
Put on thick work gloves to protect your hands from the sharp edges of the metal. The gloves also help you get a better grip on the panels as you lift them into position.
Place the first panel on the prepared roof with the edge hanging off the roof line by at least 3/4 inch. Using a 1/4-inch drill bit, drive holes through the metal panel at the location of any underlying supports, or at 12-inch intervals along the length if you are attaching it directly to the roof.
Insert 1-inch-long self-tapping wood screws, with rubber washers, into each of the drilled holes using an electric screwdriver until they are tight.
Place a second metal panel on top of the roof and overlap it so that the ridge closest to the edge overlaps the last ridge on the installed panel.
Insert 1/4-inch-diameter, 7/8-inch-long self-tapping metal stitch screws along the length of the ridge where the two pieces overlap, using a screwdriver. Space the screws at the locations of the underlying supports or every 12 to 24 inches along the length of the panel.
Continue overlapping and attaching all of the remaining metal roof panels in the same manner until the roof is covered.