Sun and temperature change
Daily and seasonal temperature swings make roofing materials expand and contract. Good fastening, flashing, and ventilation details help the system manage that movement.
Wind
Wind can lift poorly sealed shingle tabs and expose weak edges. Damage may not be easy to see from the ground.
Snow and ice
Snow adds weight and can expose heat-loss and drainage problems. Safe inspection should be left to an insured professional.
Attic ventilation
Balanced intake and exhaust help manage summer heat and winter moisture. Ventilation should be reviewed as part of the whole roof system.