Is your shingle roof twenty, twenty-five or thirty years old or older? It may be time to replace. Signs that you may need to replace include:
- Cracked, damaged or split shingles
- Granule loss or pitted shingles
- Nail pops
- Thin or cupped shingles
- Leak(s)
- Missing shingles
- Lack of ventilation
- Mold or stained roof sheathing
Old shingles 
Poorly done repairs 
shingle damage 
Poor ventilation 
Roof has failed 
Cracked shingles 
Bad flashing
