A good roofer can explain how they will resolve difficult areas on the roof and prices a specific scope of works. They work according to the documentation for the chosen covering, check the substrate and plan protective measures. Photos of finished houses alone are not enough for assessment. It is worth asking about flashings, ventilation, acceptance of covered layers and the rules for settling additional works. The way these answers are given says a lot about the quality of the collaboration. Experience with one material does not automatically mean knowledge of every system. Modular tile-effect metal roofing, long sheet metal cut to size and insulated sandwich roof panels have different details. Ask for a description of similar projects. Work of a comparable degree of difficulty says the most, not just the number of years in business.

The decisive step is to check the pitch of each roof section individually, not to average the two values. The choice of covering for a mansard roof depends on whether the given profile has a solution for the break line that ensures free water runoff, proper support and ventilation. It is worth verifying whether the permissible pitch for the steeper part also matches the gentler part and whether the planned flashing works with the sheet geometry. Colour matching alone will not make both fragments function as one tight roof.