National Center for Construction Education & Research (NCCER) Plumbing Level 1 Practice Exam

The most common material used for residential water supply piping is copper. This preference for copper is due to several advantages it offers. Copper piping is known for its durability and resistance to corrosion, which helps ensure the longevity of plumbing systems. It can withstand high temperatures and pressures, making it suitable for both hot and cold water supply.

Furthermore, copper has natural antimicrobial properties, which can help maintain water quality by limiting the growth of bacteria and other pathogens within the plumbing system. It is also relatively easy to work with regarding installation and repairs, as it can be soldered and joined using various techniques.

While other materials like PVC, polyethylene, and galvanized steel are used in specific applications or in certain regions, copper remains the standard choice for residential water supply due to its overall reliability and performance. Understanding these properties helps in recognizing why copper is often favored in plumbing systems.