There is a variety of piping material options to select from. One of the most popular choices is PEX plumbing pipes. Also referred to as cross-linked polyethylene, PEX plumbing pipes are engineered to be reliable, flexible and strong. Because of their material, they can expand and contract, making them spectacularly flexible during extreme temperatures and pressure. PEX plumbing pipes are a superior choice to consider for whole-home repiping when considering a low-cost crack-resistant alternative to copper pipes.