1. Excessive heat buildup below in summer months
2. Excessive heat loss in winter months
3. Excessive fading of furniture or hardwood floor below
4. Leaking
5. Sweating
6. Foggy/Streaky Glass
7. Broken/Cracked Glass or Acrylic
8. Twisted trims at the top of the skylight well
9. Dark gaskets can be seen exposed from below
10. Your 20 year old roof was changed but your skylights weren’t