I started installing tile roofs in 1993 and focused primarily on new construction tile roof installations and tile roof repairs all here in the Pacific Northwest. In 2010 I switched focus to working only w/ repairs to tile roofs and rot and siding repairs involving tile roofs. Many tile roof leaks are due to improper junctures of different trades - roofing to siding, roofing to brick work, etc. and knowing how to make these different exterior claddings work well together is key to building envelope success.
Verify the contractor is insured against possible damage.
Look up a contractor’s license history for license violations.
A contractor registration is required by the State of Washington if a homeowner project involves any work that increases or decreases the value of real estate or consulting on a construction project. Contractors are not required to be registered if the customer needs gutter cleaning or pruning or lawn care or window washing to be performed.