Roofing companies install roofs on buildings, repair them or replace them. A roofer uses different types of materials to repair or replace the roof of a building. There are many different types of roofs, but most roofing companies specialize in a specific type of roofing. Most roofing companies specialize in one or two kinds of roofs. A professional roofing company will take care of all of the needs of the building and will do a good job in a timely manner.