Roofs should be replaced around the 20 to 25-year mark. By this time, important materials begin to fail. If youâre not sure of the age of your roof, there are a few signs itâs time for a replacement. Curled shingles, leaks, missing shingles, mold, internal water damage, dents, and bald spots are good indicators. If your roof is new and you are experiencing these problems, call the company who installed the roof to find answers.