Repair often makes sense when
Damage is isolated, the roof is otherwise young, matching material is available, decking is sound, and the leak source is clearly identifiable.
Replacement becomes more rational when
Leaks are recurring, shingles are broadly brittle or losing granules, multiple elevations are failing, decking problems are widespread, or repair costs are accumulating on an older roof.
Ask for both scenarios
A trustworthy contractor should be able to explain the likely life of a repair, the risk that remains, and the cost difference between a focused repair and full replacement.
Next step: Use this guide to create a consistent set of questions before requesting or comparing contractor bids.