Which material is most commonly used today for hot water piping in residential applications?

The most commonly used material for hot water piping in residential applications today is CPVC (Chlorinated Polyvinyl Chloride). CPVC is favored due to its ability to withstand higher temperatures compared to standard PVC, making it suitable for hot water applications. It also has good chemical resistance and does not corrode like metal pipes, which can lead to leaks and other issues over time.

CPVC is lightweight, easy to install, and often less expensive than alternatives such as copper. It is specifically designed to handle the thermal stress that comes with hot water flow, maintaining its integrity and performance. The material's installation often requires less specialized labor, which can further reduce overall costs.

While other materials like copper and galvanized iron may still be used in some applications, they come with drawbacks such as susceptibility to corrosion (in the case of galvanized iron) or higher costs and complexities (with copper). PVC is more suited for cold water but not recommended for hot water, as it cannot handle high temperatures without deforming. Thus, CPVC stands out as the most practical choice for hot water systems in modern residential plumbing.