The answer to 'how to repair asphalt shingles' is to first inspect the damaged shingles and determine if they can be repaired or need replacement. For minor damage like cracked, curled, or missing shingles, you can often make repairs yourself. Start by cleaning the area and applying roof sealant or roofing cement to secure the shingle in place. For more extensive damage, you may need to replace the entire shingle.
To replace a shingle, carefully remove the damaged one and slide the new shingle into place, securing it with roofing nails. Make sure to match the new shingle's color and style to the existing roof. If you have significant roof damage or are unsure about the repairs, it's best to call in a professional roofing contractor.