How to Roof a Garage

Remove the old roofing and dispose of it properly. Check the laws in your area for proper disposal of old roofing materials.

Add or replace the old plywood sheets. Remove the old plywood pieces and replace them with 3/4-inch plywood sheets. Use 3-inch nails to attach the pieces to the framing around the edge of each sheet, approximately every 3 feet. You can skip this step if the old plywood is undamaged.

Cover the roof area with 30-pound roofing felt. Align the edge of the roll of felt with one vertical edge of the roof. Roll the felt over the top and down to the opposite side. Cut the felt with a utility knife. Staple it in place with a heavy-duty staple placed every 8 inches. Slightly overlap the next row and every following row for complete coverage.

Apply flashing to the edge of the roof. Align the metal pieces flush to the edge of the roof and nail them in place with roofing nails every foot. Cut any end pieces to fit with tin snips.

Measure and mark the horizontal center of the roof. Measure the entire side of the roof and divide it in half. Mark a vertical chalk line all the way up the center of the roof. From each side of this line, make a chalk line every 6 inches across the roof. This helps align the shingles across the roof.

Cut off the tabs of the shingles to create a starter row. The majority of shingles comes in short rows with tabs on one side. Use the utility knife to cut off the outer tabs. Center the first row of shingles with the center line of the roof then work across the roof in each direction and remove the tabs from each additional piece. Overhang the starter row of shingles 1/4-inch off the edge of the roof. Place four roofing nails in each shingle square at the corners.

Measure back 5 inches from the edge of the starter row and draw a horizontal line across the roof. From that line, measure back another 5 inches and create another line. These lines align the next rows of shingles to ensure they are straight.

Begin the next row. Place a tab edge at the first horizontal chalk line, overlap the initial or starter row and nail it in place. Use the vertical chalk lines as a guide for the edges to keep everything aligned. Continue in this fashion until the first side is covered in rows of shingles.

Repeat the process for all additional sides of the roof.

Create the ridge cover by cutting rows of shingles to 12-by-12 inch pieces. Use the utility knife to cut the shingles to size. Begin at the edge of the ridge or peak of the roof and center the shingles across it. Overlap the edges of the line of shingles by 1/4-inch. Use roofing nails along the edges of the shingles to hold them in place.