Roof Replacement Cost: 7 Signs Your Roof Is Done — and What a New One Costs

Replace your roof when you see three or more of these seven signs together: shingles that are curling, cupping or missing granules; daylight or water stains in the attic; a roof age past 20 years for asphalt shingles; and recurring leaks that patching no longer holds. Any one sign alone may justify a repair, but three together mean the system is failing, not a single shingle — and at that point a replacement is cheaper than the next three repairs plus the interior damage they fail to prevent.

For cost context, a typical architectural shingle roof runs about $11,200 installed nationally — see the full breakdown in our roof replacement cost guide, including state editions such as Texas and Florida. Measure your roof first with the Roofing Calculator and the Roof Pitch Calculator, so you can check any quote against your own quantities before you sign.

1. Shingles curling, cupping or clawing

Shingles curl in two ways, and both mean the shingle is done. Cupping is when the edges turn upward, exposing the shingle below to wind and water. Clawing is when the centre rises and the edges stay flat, creating a hollow that traps water. Both are caused by age, heat and moisture cycling, and both break the overlapping water-shedding system the roof depends on. A few curled shingles on a south-facing slope can be replaced individually; widespread curling across multiple slopes means the shingle stock has aged out and patching will chase failures slope by slope.

Check from the ground with binoculars rather than climbing up: look for a wavy, uneven roofline and for shingle edges lifting visibly. If you can see curling from the street, a roofer will find more up close. Curling caused by poor attic ventilation sometimes improves with ventilation fixes, but curled shingles themselves do not flatten again — the material has permanently deformed.

2. Granule loss: bald shingles and grit in the gutters

Asphalt shingles are coated in mineral granules that protect the asphalt from UV light. When granules wash off, the asphalt is exposed, bakes, cracks and fails faster — granule loss is both a symptom and an accelerator of roof ageing. Check the gutters and downspout outlets for accumulations of coarse, sand-like grit after rain; a handful after a storm is normal on a new roof, but a consistent layer on an older roof means the granules are leaving in volume. Look for bald patches — dark, smooth areas where the shingle surface shows through — on the roof itself.

Granule loss after a hailstorm is different: hail knocks granules off in random circular patterns and is an insurance matter, not an age matter. If your roof is under 10 years old and losing granules heavily, get the manufacturer warranty and the installer involved before assuming age — premature granule loss can be a defect or a ventilation problem, and both may be covered.

3. Age: the calendar is a legitimate diagnostic

Asphalt architectural shingles are rated for 25–30 years, but real-world life is usually 20–25 years depending on climate, ventilation and installation quality. Three-tab shingles last 15–20 years. Wood shakes last 20–30 years with maintenance. Metal lasts 40–70 years, tile 50+ years, slate 75–100 years. If your asphalt roof is past 20 years, budget for replacement even if it looks acceptable from the ground — the failure mode of an old roof is sudden (a storm finds every weakness at once) rather than gradual, and insurers increasingly refuse or surcharge roofs past 20 years regardless of appearance.

If you do not know the roof's age, check the home inspection report from your purchase, the permit record at the building department, or the attic for a shingle wrapper or installer label left behind. Neighbours with the same builder and build year often share a roof age — a useful proxy when records are missing.

4. Leaks that return after repair

One leak, found and fixed, is maintenance. The same leak returning after two repairs, or new leaks appearing in different places within a year, means the underlayment or the flashing system is failing across the roof, not at a single point. Water stains on attic rafters, damp insulation, daylight visible through the roof boards, and mould or musty smells in the attic are all signs that water has been entering for longer than the latest ceiling stain suggests.

Trace leaks from the attic, not from the ceiling stain: water travels along rafters and decking before it drips, so the entry point is usually uphill from the stain. If the attic shows multiple stained rafters, widespread underlayment deterioration or sagging decking between rafters, the roof system — not a shingle — needs replacing. Sagging decking is a structural warning: get it assessed promptly, because it can indicate rot or a framing problem, not just a roofing problem.

5. Moss, algae and the damage underneath

Moss holds moisture against the shingle surface and lifts shingle edges as it grows, accelerating granule loss and creating a damp environment that rots the decking beneath. Algae streaks — the black stains common on north-facing slopes in humid climates — are cosmetic by comparison, though they indicate persistent damp. A roof thick with moss, especially on shaded slopes, needs more than cleaning: cleaning removes the moss but not the lifted shingles or the damp decking underneath, and pressure washing strips granules and voids warranties. If moss covers more than a third of a slope, factor replacement into the decision rather than cleaning alone.

6. Flashing failures around chimneys, valleys and walls

Flashing — the metal that seals roof joints at chimneys, valleys, skylights and walls — is the most common leak source on an otherwise sound roof, and it is also the most commonly botched repair. Cracked caulk, rusted step flashing, and flashing buried under shingles rather than layered over them all leak. One failed flashing can be repaired properly by removing surrounding shingles, replacing the flashing and re-shingling the area. Multiple failed flashings, or flashing that was never installed correctly across the roof, indicate a roof that was poorly installed from the start — and a poorly installed roof rarely has only one defect. Ask a roofer to inspect flashing as part of any replacement quote, and make sure the quote specifies new flashing, not reused flashing.

7. Rising energy bills and attic heat

A failing roof often announces itself through the attic: summer attic temperatures far above outside temperatures, winter ice dams, and rising heating and cooling bills as insulation gets damp and ventilation fails. Damp insulation loses much of its R-value, so a roof leak that never stained a ceiling can still cost hundreds per year in energy. If your bills have risen without another explanation, check the attic for damp insulation, blocked soffit vents and daylight through the decking before blaming the HVAC system.

Repair or replace: the decision rule

Repair when the roof is under 15 years old, the damage is localised to one slope or one flashing, and the rest of the roof passes inspection. Replace when the roof is past 20 years, when three or more signs above are present, when leaks recur after repair, or when the decking is sagging or rotted. The arithmetic supports replacement sooner than most homeowners expect: a $1,500 repair that lasts two years, repeated three times, costs $4,500 and still leaves a 22-year-old roof; a replacement at $11,200 resets the clock for 25 years and restores insurability. Get two quotes for replacement and one honest assessment of remaining life before deciding — and if a contractor recommends replacement for a roof under 12 years old with a single leak, get a second opinion.