Guide to Plumbing Pipe Materials

Pipes made of brass were more common before the introduction of copper pipes, but they are still in use for certain applications. Brass pipes are corrosion- and heat-resistant. Since brass is a soft metal, it allows installers to form tight seals. Modern, lead-free brass is a great choice for water supply lines, water removal lines and gas lines (where allowed by code).

Pipes made of cast iron are rarely used these days because they are difficult to work with and heavy compared to modern plastic pipes. However, PVC will fit well with existing cast iron if repairs are required in older structures.

Copper is extremely durable, but also very expensive. With a cost that’s more than six times higher than PEX, copper is prohibitively expensive for many projects. However, since copper pipes can withstand earthquakes and are very fire-resistant, the extra durability they provide may outweigh any extra costs for certain situations. Even when copper isn’t specified for an entire job, it may be used for refrigerant lines in HVAC systems, service lines that run underground and hot and cold drinking water lines.

Chlorinated Polyvinyl Chloride (CPVC) pipes are similar to PVC plumbing pipes in appearance, but they are even more flexible. These pipes rank high in rust- and corrosion-resistance, but freezing water can cause CPVC pipes to split. CPVC pipe is a great choice for hot water delivery, hot water drains, drinking water delivery and waste and water disposal pipes.

Galvanized pipes are made of iron or steel that has been coated with zinc. This process makes the iron or steel pipes more durable and resistant to corrosion and rust. Galvanized pipes are often used for water lines, underground and outdoor applications.

Cross-linked Polyethylene (PEX) plumbing pipes are becoming an increasingly popular alternative to PVC or CPVC plumbing pipes. There is some concern about PEX pipes containing substances that could contaminate drinking water, but the material meets current environmental regulations for water pipes in the United States. PEX can be spliced into existing systems, so it works well for retrofitting and remodeling jobs.

Polyvinyl Chloride (PVC) pipes have been used in the United States since the 1950s. These white, plastic pipes are commonly available in most hardware stores. PVC pipes won’t rust or corrode, but they can warp if exposed to very hot water. The availability and flexibility of PVC compared to older types of pipes makes them a popular choice for primary water supply and drain waste applications.

Stainless steel pipes are more expensive than other options, which makes them less popular for large commercial applications. Stainless steel is very corrosion-resistant and durable, so the material is a good choice for areas where corrosive conditions exist or where pipes will be exposed to the elements.