Most homes in California have concrete tile, composition shingle or metal roofs. Some have clay tile or wood shake. Slate is used occasionally. Today’s roofing materials are very durable; the highest-quality ones can last decades. If you think you need a new roof, contact a roofing contractor to get a free estimate of the replacement cost. The re-roofing estimate should cover materials, labor and any local permits required. Costs can vary greatly based on the material you choose. In general, you pay more for a product with a longer warranty against defects and everyday wear and tear. Once you sign up with a roofing contractor, the actual installation only takes a few days, although you might have to wait a bit to get on the schedule if the company is heavily booked, which is often the case with high quality, reputable companies. Your contractor should handle any building permits related to your project.