How to Build Up Low Spots on Roofs

Pry the old shingles off the roof with a pitchfork.

Inspect the plywood sheathing on the roof, especially in the areas where the roof is low. A buckling roof can be caused by damaged sheathing.

Remove damaged sheathing by prying the nails out and lifting the sheet off the roof. Install new sheathing panels anywhere you removed damaged panels by nailing them to the roof rafters.

Lay sheets of 30-lb. roofing felt over the sheathing. Start at the bottom, and staple it to the sheathing every 6 to 8 inches. Lay the sheets flat against the sheathing, and overlap each sheet by 4 inches to prevent leaks.

Nail new flashing into place along the bottom edges of the roof and around the chimney if you had to remove the old flashing. Flashing is strips of metal which are installed around edges of the roof where water may leak.

Cut the tabs off of shingles for the starter course that runs along the bottom edge of the roof.

Place the shingles for the starter course along the bottom edge of the roof, positioning them so they extend over the edge by 1/4 inch. Drive in three nails, one in the center of the shingle and one on each side 4 inches in from the ends.

Lay the first row of singles by placing them so the tabs extend 1/4 inch over the edge of the shingles in the starter course. Drive in 4 evenly spaced nails 1 inch above the tabs.

Lay the second row of shingles, keeping them staggered from the shingles in the first row. Position the shingles in the second row so the bottom of the tabs cover the top half of the shingles in the first row. Attach the shingles to the roof by driving 2 nails into each shingle, placing them 1 inch above the tabs and 4 inches in from the sides.

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

Cut the tabs off of shingles for the ridge cap, which runs along the peak of the roof. Fold the shingles over the peak and drive in 2 nails on each side.