Start with what you can safely see
Missing shingles, curled edges, exposed fasteners, dark streaks, and sagging rooflines can signal trouble. Stay on the ground and use binoculars or a phone camera rather than climbing onto the roof.
Check the attic
After rain, look for damp decking, stained insulation, or daylight around penetrations. A musty smell can also point to trapped moisture.
Watch the age and repair history
A roof does not need to leak dramatically to need service. Repeated patching, storm exposure, and aging materials should be reviewed together by a qualified contractor.