You should consider a new roof replacement if you notice any of the following signs or encounter any of these roof problems: A lot of weather damaged and broken shingles. See old, rotted, or broken flashing. Notice missing asphalt granules. Notice curled shingles. Notice cracked shingles. Notice missing shingle strips Sagging roof Formation of Ice damns in the winter Notice growth of mold and mildew on shingles Experience roof leaking