How to Replace a Garage Roof

Remove the old shingles from the roof by prying them up with a pitchfork and pulling them off the roof.

Inspect the roof for signs of damage. Nail down any loose plywood sheathing, and if any sheathing has holes or signs of rot in it, replace it with new sheathing.

Lay sheets of 30-pound roofing felt onto the sheathing. Begin along the bottom edge of the roof and work up to the peak, overlapping the edges of the roofing felt by an inch. Attach the roofing felt to the sheathing with a hammer stapler every 6 to 8 inches.

Nail flashing along the bottom edges of the roof, alongside the chimney and in any valley created by different sections of the roof meeting. Flashing is strips of metal that prevent leaks.

Cut the tabs off of roofing shingles for the starter course. Nail the course into place along the bottom edge of the roof with four nails evenly-spaced. When positioning the shingles, hang them a quarter-inch over the edge of the roof.

Lay the first row of shingles along the bottom edge of the roof, placing them so that the bottom edge hangs a quarter-inch over the edge of the starter course. Attach them to the roof by driving four evenly-spaced nails into the shingles an inch above the tabs.

Lay the second row of shingles onto the roof, nailing them with four nails. Begin by positioning the first shingle so that it staggers with the first-course shingles in the center of the roof, and work out toward the sides of the roof when laying the other shingles. Staggering the shingles helps prevent leaks.

Continue laying shingles until you reach the peak of the roof, staggering the shingles in every row.

Cover the peak of the roof with ridge caps. You can purchase ridge caps or use excess shingles by cutting off the tabs and folding the top part of the shingle over the peak, driving in two nails on each side.