What signs indicate a roof needs repair versus full replacement?

Quick answer

Repair your roof if the damage is isolated (a few shingles, a small leak at a vent or flashing), the roof is relatively young, and the decking is solid. Plan for a full replacement if the roof is near the end of its lifespan, has widespread shingle failure or granule loss, multiple leaks across different areas, sagging or rot in the deck, or if repair costs are stacking up to more than about a quarter to a third of a new roof.

How to tell: repair vs. replacement

Signs it likely needs a repair

• Localized damage: A few missing, cracked, or lifted shingles; a small area of wind damage.
• Flashing issues: Leaks around chimneys, skylights, or wall intersections often trace back to failed flashing or sealant.
• One-off leak: Water stains near a single penetration (bath vent, pipe boot) without widespread attic staining.
• Roof age: Roof is well under its expected lifespan and otherwise looks good.

Signs it likely needs a replacement

• Widespread shingle failure: Many shingles are cupping, curling, brittle, or cracked across multiple slopes.
• Granule loss: Bald spots in many areas, lots of granules in gutters, or exposed fiberglass mat.
• Multiple leaks: Stains in different attic areas or ceilings across rooms.
• Sagging or soft spots: Deck deflection between rafters or spongy feel—points to rot.
• End-of-life age: Roof is at or past typical service life for its material (see specs below).
• Heat/ventilation damage: Widespread blistering or premature aging tied to poor ventilation.
• Storm-wide impact: Hail bruising across large areas or torn shingles on several slopes.

Typical reference specs
- Asphalt 3-tab: 15–20 years
- Asphalt architectural: 20–30+ years
- Metal (standing seam): 40–70 years
- Tile/slate: 50+ years (underlayment often 20–30 years)
- DIY-safe roof pitch: ≤ 6:12 (steeper roofs require advanced safety)
- Asphalt shingle nailing: 4 nails standard, 6 nails in high-wind zones
- Common nail length: 1-1/4" for single-layer into 1/2" sheathing

Step-by-step inspection

1. Ground scan (no ladder yet)
   • Use binoculars to check for missing shingles, uniformity, curling, and exposed nail heads.
   • Look at valleys, eaves, and ridges. Check for sagging lines.
2. Gutter check
   • Examine for heavy granules. A handful of granules after a big storm is normal; continuous shedding is not.
3. Ladder edge check
   • With a ladder stabilizer and a helper, inspect shingle pliability at the eave. If shingles crack when gently lifted, they’re brittle.
   • Inspect drip edge and look for rot at the fascia.
4. Flashings
   • Check metal around chimneys, vents, and skylights for rust, gaps, or failed sealant. Rubber pipe boots often crack at 8–12 years.
5. Attic inspection
   • During daylight, look for pinholes of light, dark stains on decking, wet insulation, and moldy odors.
   • After rain, use a moisture meter to confirm damp areas.

If you find mostly localized issues and the roof is under its lifespan, repair is reasonable. If problems appear in multiple categories or areas, replacement is more cost-effective.

Tools and materials

• Tools: binoculars, extension ladder with stabilizer, tape measure, chalk, pry bar/flat bar, roofing hammer or nail gun, utility knife, caulk gun, moisture meter, cordless drill.
• Materials (for small repairs): matching shingles, roofing nails, underlayment patch or ice/water membrane, pipe boot, step flashing, roofing cement (sparingly), high-quality polyurethane roof sealant.
• Safety: harness and lifeline, roof anchors, non-slip shoes, work gloves, eye protection.

Safety considerations

• Set the ladder at a 4:1 ratio and tie it off. Use a stabilizer to protect gutters and improve footing.
• Avoid working on wet, icy, or windy days. Keep three points of contact on ladders.
• On pitches above 6:12 or heights over one story, use fall protection or call a pro.

Practical examples

• Repair scenario: A 10-year-old architectural asphalt roof with a leak at a cracked pipe boot. Replace the boot ($10–$25), add a bead of sealant, and slide a new shingle if needed. Time: 1–2 hours DIY.
• Replacement scenario: A 22-year-old 3-tab roof with curling shingles, granules in gutters, and two ceiling stains. A patch will chase problems. Replacement avoids repeated call-backs.

Cost and time ballparks

• Minor DIY repairs: $20–$150 in materials; 1–3 hours.
• Pro repair: $300–$1,000 depending on access and scope.
• Full replacement (asphalt, 1,500–2,500 sq ft): $4–$8 per sq ft installed ($6,000–$20,000+). Deck repairs add $1.50–$3.00 per sq ft.

Tips for best results

• Match shingles by manufacturer and color blend when possible.
• Replace damaged flashing, not just shingles. Flashing is a common leak source.
• Improve attic ventilation during re-roof (ridge vent + intake) to extend shingle life.
• Keep records: photos, dates, and invoices help with warranties and insurance.

Common mistakes

• Layering over bad shingles: Adding a second layer hides problems and shortens life; often not allowed if there are already two layers.
• Relying on caulk as a fix-all: Sealant is a short-term patch, not a structural repair.
• High nailing: Nails above the nailing strip cause blow-offs and leaks.
• Ignoring underlayment and ice barriers in cold climates.
• Mismatched color/weight: Visible from the street and may affect resale.

When to call a professional

• The roof is steep or high, or you lack fall protection.
• There’s sagging, suspected deck rot, or structural issues.
• Widespread hail damage or wind damage across several slopes (consider an insurance claim).
• Complex details: chimneys, dead valleys, skylights, or multiple layers requiring tear-off.
• Uncertain diagnosis: A reputable roofer can perform a moisture scan and provide a written assessment and estimate.

A focused inspection and a few objective checks—age, scope, and severity—will tell you whether a repair buys you meaningful time or if a full replacement protects your home and budget better over the long term.