Measure accurately before ordering shingles. Shingles sell in units called "squares," and each square is equal to 100 square feet. In addition, you need starter shingles that also come in bundles but you'll only use them on the first row on either side of the garage roof. The last shingle type you need fits on the ridge of the roof, extending from one end to the other. Most shingle bundles have a measuring chart on the back to help you purchase the correct amount.
Prepare the roof for shingling by removing old layers of shingles (if applicable) and installing new felt paper or roofing paper on the plywood. Use a staple hammer or a regular hammer and roofing nails to hold the felt paper in place. If you live in a windy area, you can purchase small thin metal "dots" and hammer nails in the middle of each one to help hold the paper down. Trim all paper flush with the roof edges.
Install gutter apron along the bottom edge of the roof, and install metal roofing edge along the gables. This gives your roof a straight, clean line and allows you to connect gutting to the roof later.
Begin with the bottom row on one side and pop a chalk line from one edge of your roof to the other to form a horizontal guideline for your starter shingles. Measure up from the gutter apron to the exact width of a started shingle and pop the chalk line. Install the first row of starter shingles, making sure the top of each one is positioned on the chalk line before nailing in the designated nailing area at the top of the shingle. Avoid driving a nail anywhere but in this area.
Offset the next row of shingles to keep the seams staggered. This provides a water-resistant surface on your roof. However, it will also cause you to have an overhang on the edge of the roof. Trim this overhang flush with the metal roofing edge as you go. Place and attach shingles in a straight row. Repeat this process with the subsequent rows, working your way to the top of the roof. The final row must extend to within 6 inches of the top ridge of the roof in order for the ridge shingles to cover the layer.
Follow the same process on the other side of the roof. When both sides are shingled, you'll have a narrow strip of felt paper showing only at the ridge.
Position the end pieces of ridge shingles first and work your way to the center. As you move toward the center, each subsequent ridge shingle will overlap the previous one. In the very center, one ridge shingle will overlap the shingles on each side. Make sure you measure and center this shingle accurately for a uniform look.
Things You Will Need
- Roofing felt
- Staple hammer
- Roofing nails
- Chalk box with string
- Utility knife with hook blades
- Gutter apron
- Metal roof edging
- Ridge cap shingles
- Safety equipment (harness, goggles)
- Trim all overhanging shingles immediately to keep from putting too much weight on the metal roofing edge and the gutter apron.