Start with age and condition
One failed boot or isolated wind-damaged area may be repairable. Widespread wear, repeated leaks, brittle material, and soft decking point toward replacement.
Repair often makes sense when
- Damage is isolated
- The surrounding material remains sound
- The deck is dry and stable
- The failure is a flashing, vent, or small section
Replacement often makes sense when
- Leaks appear in several areas
- Shingles are brittle or losing granules broadly
- Multiple slopes are damaged
- The roof is near the end of its service life
Ask for the tradeoff
Compare repair cost with the useful life it is likely to add. A clear contractor should explain both paths when both are reasonable.