To repair damaged shingles, lift the shingles above the damaged area, and remove nails that impede the shingle from sliding into a firm position. Fix curled-back shingles by reattaching them with asphalt roof cement or a caulking gun. Torn, decaying or missing shingles must be replaced with new ones.
- Remove damaged shingle
Remove the damaged shingle by lifting the edges of surrounding shingles. Carefully remove nails with a hammer or pry bar. Gently slide the damaged shingle out, and scrape the exposed roof of any loose or brittle residue. Check for any protruding nails left in the roof and replace, if necessary.
- Slide new shingle into place
To streamline the entry of the new shingle, slightly curve its back corners with a utility knife. Slide the new shingle into place with its front edge aligned with the shingles on each side and the back edge aligned under the shingles in the row above it.
- Fasten shingle
Lift the corners of the overlapping shingles, and secure the top of the new shingle with galvanized roofing nails. Drive nails through each corner of the new shingle. Cover nails with roof cement, and smooth the overlapping shingle edges. After replacing the damaged shingles, inspect any line of cement where two surfaces meet.