How to Shingle a 3-Tab Roof

Install a starter course at the bottom edge of the roof first. Use special starter strips or shingles, which some companies make, or cut off the tabs on enough shingles to cover the bottom edge of the roof using a utility knife. Use trimmed shingles for starters. Make sure metal drip edge flashing is nailed on first.

Lay the first shingle with the bottom just over the edge of the drip edge and the outside edge aligned with the decking. Put the cut side up if using trimmed shingles. Run a bead of roof caulking or cement along the bottom of the decking to seal the shingle bottom. Nail the top edge of the shingle to the decking with galvanized shingle nails and a hammer. Use 3 nails per shingle, one near each end and one in the middle. Fill a complete bottom row.

Set the next row of shingles with the tabs reaching to the edge of the starter course. Fasten each shingle with 4 nails about 3/4-inch above the tab cuts of each shingle. Work across the roof. Start the next row of full shingles by cutting one shingle the width of one tab, so the seams will not align. Place these shingles so the bottom of the tab just touches the cut line of the shingle below. Work to the peak alternating full and trimmed shingles on the roof end to keep seams apart.

Shingle around vents, chimneys and other vertical protrusions by running shingles under the bottom side of the metal flashing around those openings and about halfway up its sides. Shingle over the top part of the flashing, trimming shingles as needed to fit. Run a bead of cement around the flashing under the shingles. Install counter-flashing on chimneys; this is a separate metal strip put into the mortar joints of the chimney and extending down over the roof.

Bend shingles over ridges and valleys, overlapping sides, so each layer has a full shingle coming from the right with another full shingle overlapped from the left and reversed on the next course. Cover peaks with special cap shingles or with cut-off tabs bent over the peak. Nail peak shingles with one nail on each side of the roof. Run caps so the end of one covers the nails on the previous one. Seal the nails on the last cap with roofing cement.