Possible signs that your roof may need to be changed:

1. Shingle edge curled or shingle tab is cupped.
2. Belved spot where granulele is missing.
3. Cracking horns
4. Your roof is at least 20 years old
5. Getting neighboring new roof
6. The roof just looks old and abandoned.
7. Dark stacks
8. Moss mouse roof surface that does not have many sunlight, especially in cooler, humid climate.