To install rolled asphalt roofing, first place a drip edge that extends further from the roof's natural edge to encourage water to drip into the gutters. Clear the roof's surface of debris using a broom, and ensure that nails and screws are firmly embedded in the roof. Measure the roof's valleys, and cut the rolled roofing in 18-inch widths using a utility knife. Center the pieces in the center of the valleys, and secure with short roofing nails.
Use an uncut, full-width piece of rolled roofing to cover the first piece. Use the same type of nails to secure it. All nails should be at least 1 inch from the edge of the sheet and 6 inches apart. Repeat this for all of the roof's valleys.
Start at the bottom of the roof, vertically measure 35 inches, and mark the measurement with chalk. Using rolled roofing measuring the entire length of the roof, start at the mark, and nail all edges of the sheet down. The sheet should overlap the drip edge. Repeat this process until the entirety of the roof's bottom is covered.
From the edge of the installed rolled roofing, vertically measure 34 inches, and mark with chalk. Cut a piece of rolled roofing according to the roof's measurements. Before installing, place 2 inches of roofing cement along the top of the first row of roofing. Spread the second row from the marked line and over the roofing cement. Nail down all edges, and continue this process until the roof is fully covered.