Start with repair versus replacement
Ask what evidence supports the proposed scope. For a leak, request an explanation of the likely entry point and whether a targeted repair is reasonable before assuming the full roof must be replaced.
Compare material and installation details
Quotes should make it possible to compare shingles or other roofing systems, underlayment, flashing, ventilation, disposal, cleanup and warranty terms.
Ask about permits, insurance and warranties
Confirm any municipal requirements that apply to the project and ask the contractor for current information about insurance and workmanship warranties.
Plan for weather and property protection
Ask how landscaping, driveways and neighbouring properties will be protected and what happens if weather interrupts the job.