Most homeowners don't think about their roof until something goes wrong. Then they're faced with a question that's hard to answer from the ground: does this need a $15,000 replacement, or a $400 repair?
This guide walks you through the actual diagnostic signs we use during inspections. Five of them mean replacement is likely the right move. Three of them look concerning but typically just need a small repair.
If you're seeing two or more of the replacement signs together, it's almost certainly time to plan for a new roof.
5 signs you need a full replacement
1. Curling, cupping, or clawing shingles
Healthy asphalt shingles lay flat against the roof. As they age, the asphalt loses flexibility and the shingle edges start to curl upward (curling), the centers start to dish (cupping), or the corners start to lift (clawing). Once a significant portion of your roof shows these patterns, the shingles are no longer creating a consistent water-shedding surface.
Curling and cupping accelerate over time and don't reverse. Once a roof reaches this stage, replacement is the right move — typically within 1-3 years of first noticing the pattern.
How to spot it: from the ground or from a window, look for shingle edges that visibly lift away from the roof. The pattern is usually most obvious on south- and west-facing slopes that receive the most sun.
2. Significant granule loss across the roof
Asphalt shingles have ceramic granules embedded on their surface. The granules give the shingle color and protect the underlying asphalt from UV. As shingles age, granules wash off — slowly at first, then faster.
You'll see this two ways:
- Bare spots on the roof where the underlying black asphalt is visible
- A heavy concentration of granules at the base of downspouts or in gutters
Some granule loss is normal throughout a shingle's life. Heavy granule loss — to the point you can see large patches of exposed asphalt — means the shingles are at end-of-life. Without granule protection, UV degrades the asphalt rapidly and the roof will fail soon.
3. Multiple leaks in different locations
One leak is a repair. Multiple leaks in different parts of the home, especially within the same year or after the same storm event, suggest systemic failure rather than isolated damage. Common patterns:
- Leaks at multiple roof penetrations (vents, chimneys, skylights) at once
- Leaks that recur in the same spot after a repair
- Leaks that show up in different rooms simultaneously after major storms
- Water stains expanding outward from a single point on the ceiling
When the underlayment beneath the shingles has begun to fail, water finds new paths every storm. Patching one path just diverts water to find another. At that point, full replacement (with new underlayment) is the only durable solution.
4. Roof age plus visible aging
If your asphalt roof is 22+ years old AND showing any of the cosmetic signs above (curling, granule loss, dark streaks, missing shingles), it's at end-of-life regardless of any specific defect. Architectural asphalt has a 22-28 year typical lifespan in Georgia (see our roof lifespan guide) — past that range, the underlayment, sealant, and flashings are all aging together.
You can sometimes squeeze 2-3 extra years out of an old roof with patching, but it's diminishing returns. Most homeowners reach a point where they're spending $1,000+ per year on repairs and finally bite the bullet on replacement.
5. Sagging, soft, or visibly deformed roof areas
This is the most serious sign — and often the most ignored, because it builds gradually. A healthy roof has a clean, uniform plane on each slope. Visible dips, sags, or wavy patterns indicate that the underlying decking (the plywood or OSB sheathing) has been compromised, usually by long-term moisture exposure.
Once decking is failing, you have a structural problem, not just a roofing one. Replacement requires not just new shingles but tearing back to the rafters, replacing the damaged decking, and rebuilding the roof system from scratch. Don't ignore sagging — and don't walk on a sagging roof yourself.
If your roof shows even two of the five signs above — especially curling + granule loss, or age + multiple leaks — full replacement is almost certainly the right move. We can confirm during a free inspection.
3 signs that look bad but usually just need a repair
1. A few missing shingles after a storm
One or two missing shingles after a windstorm is usually a repair, not a replacement. As long as the surrounding shingles are intact and the underlayment isn't damaged, we can replace the missing shingles, re-seal the surrounding ones, and the roof is back to full function for $300-$500.
The replacement-vs-repair line is usually around 5-8 missing shingles in a single area. Beyond that, the wind likely damaged the seals on adjacent shingles too, and isolated repairs become unreliable.
2. Black streaks and discoloration
The vertical black streaks you see running down many older roofs are not damage — they're algae (Gloeocapsa magma). Algae feeds on the limestone filler in shingles. It's cosmetic only and doesn't shorten roof life.
Solutions:
- Have the roof professionally cleaned with a manufacturer-approved low-pressure sodium hypochlorite solution. Don't use a pressure washer — it strips granules and accelerates real damage.
- Install zinc strips near the ridge, which release zinc oxide during rain and inhibit algae growth.
- If you're due for replacement anyway, choose algae-resistant shingles (GAF StainGuard Plus, CertainTeed StreakFighter).
None of these is a replacement situation by itself.
3. Damaged flashings or boots
The metal or rubber components around chimneys, skylights, vent pipes, and roof penetrations are called flashings or boots. They wear out faster than shingles — pipe boots typically need replacement at 8-12 years, before the surrounding shingles do.
If you have a leak around a vent pipe or chimney and the surrounding shingles look fine, you almost certainly need flashing replacement, not a roof replacement. This is a $200-$800 repair depending on the component.
Don't let a contractor sell you a full replacement for a single failed boot. We replace boots and flashings as standalone repairs all the time.
What to do next
If you're seeing one or more of the replacement signs above, the most important next step is to get an honest inspection. Some contractors will recommend full replacement when a repair is appropriate (it's a bigger sale). Others will sell repairs forever even when replacement is the right move (less commitment for the homeowner). The right contractor tells you the truth, even when it costs them the bigger job.
Bishop JD Roofing offers free inspections across North Georgia. We'll tell you straight whether you need replacement or whether a repair makes more sense. About 30% of the inspections we do end with us recommending a repair rather than a replacement. We're not trying to sell every homeowner a new roof.
Frequently asked questions
How do I know if I need a full replacement or just a repair? +
Repairs make sense for isolated, recent damage on an otherwise healthy roof. Full replacement makes sense when damage is widespread, the roof is approaching end-of-life regardless, or you're seeing multiple symptoms (curling, granule loss, leaks) at once. We give you an honest assessment during the free inspection — there are absolutely cases where a $400 repair is the right answer rather than a $15,000 replacement.
Can I just replace the damaged section of my roof? +
Sometimes. Single-slope replacements work when damage is confined to one slope and the rest of the roof is in good condition. The new shingles won't perfectly match weathered shingles on adjacent slopes, but the function is sound. We do this regularly for storm claims that are scoped to a single slope. For widespread damage or older roofs, full replacement is more economical.
Are dark streaks on my roof a sign I need a new one? +
Usually no. Black or dark green streaks running down slopes are typically Gloeocapsa magma algae, which is cosmetic. Cleaning with a manufacturer-approved solution can remove most of it. Algae alone isn't a reason for replacement, though it does indicate the roof has been in place long enough to develop biological growth (typically 7+ years).
Will my insurance cover a roof replacement for old age? +
No. Insurance covers sudden, accidental damage from storms, fallen trees, fires, and similar events. Wear and tear, age, and gradual deterioration are specifically excluded from every homeowner policy. If your roof is failing because of age, you'll pay out of pocket. If a storm damaged an aging roof, the storm damage may be covered (often resulting in a full replacement when the existing roof can't be matched).
How long can I wait if I have one or two of these signs? +
It depends on the specific signs. Single missing shingle: weeks. Active leak: days. Multiple curling shingles + granule loss + 18+ year age: months at most. Active sagging or visible decking damage: immediately, before someone gets hurt. If you're not sure how urgent your situation is, schedule a free inspection — we'll tell you the actual timeline.