To ensure a comfortable living environment, a plumbing system should meet the demands of the homeowner. Plumbing should be durable and free from leaky connections, joints, or fittings; the more connections in a home's plumbing system, the greater the chance that one of these connections will fail over time, leading to water damage, rot, and even mold.

Today, a majority of homes use copper pipe plumbing systems for water distribution. Copper pipe is softer and easier to work than other metals like lead and iron, and it's relatively non-toxic. The ready availability and water-resistant properties of copper continue to make it the first choice for most homebuilders. But as new materials are developed and new technologies are created, copper piping is no longer the best bet for avoiding comfort issues and plumbing-related warranty claims. A relative newcomer, PEX, typically known for its use in radiant floor heating, is quickly gaining popularity as an excellent material for water supply systems.

Copper pipe plumbing systems
The conventional copper pipe method of plumbing requires that the water supply line branch at the water heater, with the hot water line running through the water heater and then running in tandem with the cold water line throughout the home. Smaller-diameter lines branch off from the main lines to serve water-using fixtures and appliances. This plumbing system requires more fittings, and pipe sizes vary according to the loads they carry. With this system, the water supply is subject to pressure loss if several fixtures on a branch are used at once.

Copper pipe also has to be run around obstacles, so more connections and intersections are required. Sweating and connecting the joints of a copper plumbing system takes time. Furthermore, after construction, the pipe connections are inaccessible. Since many of the joints are hidden behind finished walls, if there's a leak, the homeowner may not realize it until substantial water damage has been done to the home. Repairs from water leaks can be costly and difficult.

PEX plumbing systems
A new method for water distribution in residential homes is gaining popularity among homebuilders. Known as PEX plumbing, cross-linked polyethylene (PEX) is a flexible plastic piping composed of individual molecules that have been permanently linked together. Cross-linking the molecules creates a durable, stable plastic that can’t be melted and reshaped. Copper and CPVC are both reliable materials for plumbing systems; however, PEX tubing has several important advantages that make it the best choice for water distribution:

• PEX requires fewer connections. The tubing is available in long coils and is flexible enough to bend around obstructions without the use of connections. Fewer connections mean fewer opportunities for connections to leak and cause water damage.
• PEX is easier to install. Fewer fittings and a lightweight, flexible nature mean PEX tubing can be easily run around and through obstacles in the home and can be installed more quickly – resulting in lower labor costs.
• PEX reduces maintenance and repair costs. Service is relatively simple, since manifolds are corrosion-resistant and the connections are visible. PEX is plastic, so it doesn’t experience pitting either.
• PEX offers better energy efficiency. It reduces the amount of heat lost from water in the piping, increases the response time of hot water, and decreases the amount of energy the water heater uses to deliver hot water.

To ensure a comfortable living environment, a plumbing system should meet the demands of the homeowner. PEX offers homeowners too many advantages to ignore. Although copper and CPVC have good track records in the plumbing industry, PEX's reliable, flexible nature, as well as it's ability to increase energy efficiency and reduce installation time, make it the best choice.

For more information on PEX versus copper and CPVC, download this plumbing comparison chart from BuildIQ University’s online training course, Mechanicals: Plumbing. Also check out our related article about  how to inspect a PEX plumbing installation.