Detailed Answer
The repair vs. replace decision comes down to three factors: roof age, extent of damage, and cost comparison.
Choose REPAIR when
- Roof is less than 15 years old
- Damage is confined to one section (less than 25% of total area)
- Only a few shingles are missing or damaged
- A single leak can be traced to a specific flashing or vent boot failure
- Repair cost is under $2,000-$3,000
- The rest of the roof is in good condition
Common repairs and costs
- Replace a few shingles: $200-$500
- Fix a flashing leak: $300-$600
- Replace a pipe boot: $150-$350
- Patch a small area (under 100 sq ft): $500-$1,200
- Repair ridge cap: $300-$700
Choose REPLACEMENT when
- Roof is 20+ years old (for asphalt shingles)
- Multiple leaks in different areas
- Widespread curling, cracking, or granule loss
- Visible sagging in the roof deck
- You are planning to sell within 1-3 years
- Repair costs exceed 30% of full replacement cost
- Two or more layers of shingles already exist
- Extensive storm damage across the entire roof
The break-even math
If your roof has 5-8 years of life remaining and needs a $3,500 repair, you are spending $3,500 for just 5-8 more years. A full replacement at $12,000 gives you 25-30 years. Per year, the replacement ($400-$480/year) is actually cheaper than the repair ($440-$700/year).
Mixed approach: Sometimes a partial replacement makes sense. If one section has different exposure or was damaged while the rest is sound, replacing just that section can be cost-effective. Discuss this option with your contractor.