Maybe you're building your own home. Maybe you're working on a kitchen or bathroom remodel. Or perhaps the original copper or galvanized plumbing in your home needs to be replaced. Whatever the project is, you're going to have to make a choice about what kind of piping you want to use for your water distribution system. While there are plenty of options to choose from, PEX and CPVC are two types of pipe that are commonly used for residential purposes. To help you make the best decision for your specific needs, we've taken the time to lay out the similarities, differences, benefits, and drawbacks of each type of pipe.
What is PEX Pipe?
PEX pipe originally gained significant U.S. market share when polybutylene pipe fell out of favor with an onslaught of lawsuits dictating a need for a replacement. Unlike traditional steel, copper, or plastic pipe that comes in rigid sections, PEX pipe is made of a cross‐linked polyethylene material that is flexible. This makes it easier for plumbers to install and can be bent around corners and fit into tight spaces.
Advantages of PEX
There are a host of reasons why you might want to use PEX pipe in your home. To start, PEX pipe is approved for hot and cold water plumbing systems and recirculating/hydronic heating systems in all mechanical and plumbing codes in the U.S. and Canada. You'll never have to worry about complying with local regulations where you live.
PEX pipe is also adaptable to extreme weather conditions ranging from temperatures well below freezing all the way to 200° Fahrenheit. Whether you live in the far north where winters are long or in the desert southwest where temperatures can be sweltering in the summer, PEX pipe is sure to maintain its integrity. Due to its flexibility that allows it to expand and contract, PEX pipe is considerably more burst‐resistant than plastic pipe that is rigid and prone to cracking.
PEX pipe is easy to install, requires fewer connections, and costs less per linear foot than other pipe options. All of these factors make PEX pipe a cost‐efficient yet durable option if you're on a budget. Most PEX pipe comes with a warranty of 25 years. This gives you the comfort of knowing that if anything should ever happen, it won't cost you an arm and a leg for repairs.
Disadvantages of PEX
The most glaring disadvantage of PEX pipe is that it can't be used outdoors or exposed to UV rays. If any part of your water distribution system is exposed to sunlight, PEX pipe won't last.
While it can be installed in driveways or sidewalks as part of ice melting systems, PEX pipe is susceptible to damage from rodents chewing on it. This can cause leaks or allow heat to escape, meaning affected areas might not thaw.
What is CPVC Pipe?
CVPC pipe is made of thermoplastic and is used in sprinkler and drain lines as well as water‐based heating systems. From the outside, CPVC pipe resembles the PVC pipe that preceded it. CVPC pipe was developed in the 1980s and has proven to be more durable, safer and easier to install, and longer lasting than the PVC pipe of before.
Advantages of CPVC
CPVC pipe is non‐toxic. This means it won't leach chemicals even if they have been sitting inside the pipe for a long period of time. CPVC pipe is also resistant to chemicals, their residues, and scale buildup, meaning that the purity of your water won't be compromised. Because CPVC pipe is made of plastic, you won't have to worry about electrolysis (the process by which water breaks down into oxygen or hydrogen gas, which can be highly toxic).
The flame‐resistant quality of CPVC pipe is another attractive quality. Since it won't burn without a flame source, you won't have to worry about it melting in the event of a residential fire.
CPVC pipe can also save a lot of energy, and therefore money, on heating and cooling bills. Because it is well insulated, both hot and cold water retain their temperatures for longer periods of time. This considerably lessens the total amount of water you use, and your wallet will thank you for it at the end of the month.
Disadvantages of CPVC
The most common complaint about CPVC pipe is that drinking water can sometimes taste like plastic. Though it is not harmful and doesn't contain any hazardous substances, the taste can be less than appetizing.
The fittings used to fix CPVC pipe can crack or warp if they are dropped or the foundation of the structure shifts during a remodel or earthquake. This can lead to leaks that can be difficult to detect if they aren't in a place that's readily visible.
Even though CPVC pipe is highly resistant to significant temperature shifts inside the pipe, temperature swings outside the pipe can cause them to expand. This most often happens when pipes freeze and can lead to cracks, leaks, and bursts that can be disastrous.
Which Pipe is Best for You?
Making the choice between PEX or CPVC pipe depends on a number of factors. Both types of pipe have qualities that make them especially useful in certain situations and not so much in others. If you're going to be installing pipe indoors and bending it around corners, PEX pipe might be your best choice. On the other hand, if you're worried about longevity of pipe that's outside and exposed to the sun, CPVC pipe is the way to go (although it is still recommended to protect the pipe from direct sunlight). Whatever type of pipe you choose, it's important to consider your budget, where the pipe will be installed and for what purpose it will most often be used.