How to tell if your roof needs replacing (and when it does not)
A roof is the one project where being late is expensive in a way the others are not. Water that gets past the covering does not stop at the ceiling — it finds insulation, drywall, framing and, eventually, the things you keep in the house. But being early is expensive too: replacing a roof with eight good years left throws away roughly a third of what you paid.
Start with the material and the age
Expected service life varies more by material than by anything else:
- Three-tab asphalt shingle — 15 to 20 years
- Architectural (dimensional) asphalt — 22 to 30 years
- Wood shake — 20 to 30 years, and highly dependent on maintenance
- Concrete or clay tile — 40 to 60 years for the tile itself, but the underlayment beneath it typically needs replacing at 20 to 30
- Standing-seam metal — 40 to 70 years
- Flat / low-slope membrane — 15 to 25 years depending on the system
The tile case catches people out. A tile roof can look immaculate at year 35 while the felt underneath — which is what actually keeps water out — has failed completely. A "lift and relay" replaces the underlayment and re-uses sound tile, and costs meaningfully less than a full tear-off.
The signs that actually mean something
From the ground, with binoculars if you have them: shingles that are curling at the edges or cupping in the middle, bald patches where the granules have worn off, missing or slipped pieces, and any sagging in the roof line. In the gutters, a heavy accumulation of granules — they look like coarse sand — means the surface is wearing through.
From inside the attic, on a bright day with the lights off: any daylight coming through the boards, dark staining on the underside of the sheathing, or a damp, musty smell. Staining that is dry and old may be a leak that was already fixed; ask when.
The single most telling sign is not on the roof at all. It is a repair that keeps coming back. A leak that has been patched twice in the same place usually means the problem is the system, not the spot.
What a real inspection covers
An inspection worth having looks at more than the field of the roof. Most leaks start at penetrations and transitions: the flashing around chimneys and skylights, the valleys where two planes meet, the vent boots, and the edge details. Ask specifically about those. Ask whether the sheathing feels solid underfoot. And ask for photographs — a contractor who will not show you what they saw is asking you to buy on trust alone.
When waiting is the right answer
If your roof is mid-life, has no active leak, no daylight in the attic, and the granule loss is modest, the honest advice is usually to do nothing and re-check in two years. A single failed vent boot is a $200 repair, not a $15,000 one. Be skeptical of an inspection that arrives free, unsolicited, immediately after a storm and concludes that a full replacement is needed — that sequence is a sales process, not a diagnosis.
If you are replacing, get the contingency priced first
Nobody knows the condition of the sheathing until the old roof is off. The most common way a roofing quote grows is a mid-job discovery with no agreed price attached to it. Ask, before signing: what is the per-sheet price for replacing damaged sheathing, and how will you show me what needed doing? A contractor who answers that clearly is telling you how the rest of the job will go.
See what a re-roof would cost on your specific home — measured from your roof rather than a city average, free and with no signup.