The following are signs that your roof may be failing: missing shingles, loose shingles, evident sagging, interior water damage, folded or dented shingles, curled, cracked or blistered shingles, shingles with holes, granules in your gutters or on the ground, missing or damaged flashing. A professional and trustworthy roofing specialist needs to inspect your roof to assess the cause and extent of your roof damage and will then give you the appropriate recommendations of getting a roof repair or an entire roof replacement.