A roof rarely fails all at once. It sends signals for months or years first. Catching them early can mean a $400 repair instead of a $12,000 replacement — or, if several signs appear together, knowing it is genuinely time to re-roof rather than patch again.
1. Age
Age alone is a warning sign. Asphalt shingle roofs last about 20–30 years; if yours is past 20 and showing any other symptom on this list, you are near the end of its service life. Knowing the install date is the single most useful fact for judging the rest.
Age past 20 years + any second symptom = plan for replacement, not another patch.
2. Curling and granule loss
Look at the shingle surface. Curling or clawing edges mean the shingles have dried out and lost flexibility. Granule loss — bald, shiny patches, or granules collecting in your gutters and downspouts — exposes the asphalt mat to UV and accelerates failure. A few scattered granules after a new install is normal; piles of them on an old roof are not.
- Curled or cupped shingle edges
- Bald spots where granules are gone
- Cracked, brittle, or missing shingles
- Granule sludge in gutters
3. Leaks and stains
Interior signs often appear before exterior ones become obvious. Water stains on ceilings, peeling paint near the roofline, or damp insulation in the attic all point to a compromised roof or flashing. Daylight visible around vents or chimneys means flashing has failed and water has a path in.
4. Sagging and daylight
A sagging roofline is the most serious sign — it suggests the decking or structure beneath is rotting or holding moisture, and it warrants prompt professional inspection. Combined with widespread surface wear, sagging usually tips the decision firmly toward full replacement.
If you are seeing several of these signs, get an estimate before the next storm forces your hand. The roof replacement cost calculator gives a quick total for your home's size and material — typical complete jobs land in the $9,000–$18,000 range around an $11,000 national average.
Lifespan and cost figures are blended national estimates; see our methodology.