01
Understand the service components
A contractor may need to organize access, protect the building, locate the problem, remove failed work, and make a weatherproof repair. These tasks remain even when only a few pieces of slate are replaced. Ask for a description of the planned visit and whether diagnosis is included, rather than judging the quotation from the material count alone.
02
Combine work when appropriate
Share other known concerns before the visit so the contractor can decide whether they can be assessed at the same time. Do not assume that every nearby defect can be repaired with the same equipment or materials. A clear visit scope lets you compare quotations fairly and understand which findings may need a separate proposal.