The signs you need roof repair are ceiling stains, missing or cracked shingles, granule loss, rusted or lifted flashing, attic daylight, and a sagging roofline — localized failures of a roof's weatherproof barrier, per GAF and NRCA guidance.
Each sign marks a specific failure point that a targeted repair addresses before the damage spreads to the deck and structure.
What Interior Signs Point to a Roof Leak?
Brown or yellow ceiling and wall stains that spread or darken after rainfall indicate an active roof leak or trapped attic moisture, per GAF and This Old House inspection guidance. The stain marks where water has already traveled inside, not where the roof failed.
Daylight visible through the roof deck from inside the attic indicates holes in the decking and shingles, a sign that points toward replacement rather than a patch, per This Old House. Water enters at one detail and travels before showing as an interior stain, so a thorough diagnosis traces the moisture path from ridge to eave to the root-cause detail, per Integrity Home Exteriors repair-process guidance. Damp insulation, musty odors, or discoloration in the attic confirm the path even when the roof surface looks intact from the ground.
Which Exterior Signs Indicate Shingle or Flashing Failure?
Missing, cracked, or torn shingles expose the underlayment and the roof deck to wind-driven rain, per GAF inspection guidance. Wind blow-off and impact strip the protective layer, leaving the assembly beneath open to water.
Granule loss with sandy grit in gutters indicates shingles nearing end of life; granule loss exceeding 30% of the surface is the common rule-of-thumb for beyond repair, per GAF. Below that threshold, the wear stays localized and a targeted repair restores the water layer.
Rusted, lifted, or bent flashing at chimneys, walls, skylights, and valleys ranks as the most common leak source, because flashing seals the roof transitions that an estimated 90–95% of leaks trace back to, an industry estimate attributed to the NRCA. The metal corrodes and the sealant laps lift, opening the joint where two roof planes meet.
When Does a Sign Point to Replacement Instead of Repair?
A sagging ceiling or roofline indicates sheathing decay from prolonged moisture and ranks as a structural priority, per GAF. Sagging signals that water has reached and weakened the wood beneath the covering, beyond what a surface patch resolves.
The repair-versus-replace threshold turns on how much area the damage covers: repair favors an asphalt roof under 10–15 years old when damage stays localized and covers under 25–30% of the roof area, while damage exceeding 25–30% of the area, or one repair approaching 50% of replacement cost, favors replacement. The 25–30% area rule and the 50% cost rule are contractor-consensus thresholds. Attic daylight and a sagging roofline are the two signs that most often push a roof past the repair threshold.
Catching these signs early — a fresh ceiling stain, a few missing shingles, grit in the gutters, or lifted flashing — keeps damage localized, where a targeted repair restores the weatherproof barrier instead of forcing a full replacement.