Plumbers are professionals who assemble, install, and repair pipes, fittings, and fixtures that carry water and gas according to plumbing codes and specifications. They work with piping systems, install sinks, tubs, and other kitchen fixtures and bathroom fixtures. A plumber ... gives plumbing estimates, does general maintenance, and can work on waste disposal systems. In new construction, a plumber will follow the blueprint and work as a subcontractor for your contractor. The pipes he or she works with can be made of copper, glass, lead, plastic, ceramic, cast iron, or steel. New construction plumbing is checked the building inspector, but on home repair or home renovation it is even more essential to get good references and find the right plumbing company.