Building materials generally include cement, sand, wood, wood panels, gypsum board, keel, bricks and tiles, structural components, various pipes, electrical plumbing accessories, steel bars, plastic plates and small equipment for building construction tools, as well as building decoration materials such as glass, stone plates, various floors, various lamps, paints and accessories, various doors and windows, small hardware, rubber and plastic accessories, wallpaper wallcoverings, etc., is a relatively large classification in the manufacturing industry.