Pipes can be made of a range of materials, depending on when your home was built. From the 1970s to 2000, copper was the material of choice. It typically lasts around 50 years before needing replacement. There are still some cast iron pipes in homes from the 1960s and galvanized steel from the 1970s. Most pipes today are made of some sort of plastic or derivative. The most common options are PEX, PVC, and PB.