How can I fix buckling shingles?

Fixing buckling shingles, which appear as wavy or distorted areas where shingles are raised and not lying flat against each other, requires addressing both the symptom and the cause. Buckling is often caused by moisture in the roof deck, improperly installed underlayment that wrinkled, or plywood decking that was installed without proper spacing and expanded when wet. For minor buckling affecting only a few shingles on a relatively new roof, you can try to repair by carefully removing the affected shingles. Lift the shingles above with a pry bar, remove nails, and cut out the buckled section. Inspect the underlayment underneath. If it is wrinkled, cut out the wrinkle and replace with new underlayment or flatten it and staple it down. Ensure the deck is dry. Install new matching shingles, nailing properly and sealing with roofing cement. However, if buckling is widespread across large areas, it indicates a systemic issue such as lack of attic ventilation, wet decking installed during original roofing, or structural movement, and spot repairs will not last. In that case, you need to correct the ventilation, allow the deck to dry, and often perform a full tear-off replacement. Buckling should not be confused with curling, as buckling often involves the underlayment or deck moving, while curling is shingle aging. Never simply nail down buckled shingles without fixing the cause.