Potential Plumbing Problems Lurking in Walls

Plumbers weigh in on the piping material that some say is increasingly causing problems in water systems.
Potential Plumbing Problems Lurking in Walls
Copper piping is a mainstay in the plumbing world, but for a less expensive plastic alternative plumbers have varying opinions.

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Jeff Grzetich, of Plumb Crazy Plumbers in St. Petersburg, Florida, used to install CPVC piping in homes. But when too many repiping jobs started requiring follow-up visits, he knew he had to find an alternative. 

“Over time the CPVC is getting brittle and cracking, so I no longer use it,” he says. “Occasionally I have to use it on a repair when the system already has it in there, but I don’t use CPVC for repipes anymore.” 

Grzetich is not alone. Though still an accepted material for piping, CPVC is losing favor with some plumbers as they encounter various problems with it while on the job. They say it’s less a matter of if issues will occur but when. 

“On some houses it lasts quite a long time before it gets brittle. Other houses, I think it has more to do with temperature and placement of the pipe than anything,” Grzetich says. “But over time, any kind of CPVC is going to get brittle and eventually crack. And once it cracks, it cracks pretty good and then you’re going to get a steady stream of water out of it. It’s not like copper where you get a leak in it and it just drips. Once CPVC cracks, it goes. I was at a house the other day, and there were three leaks in the ceiling, all from CPVC. And when I tried to repair them, the pipe just kept cracking.” 

Sean Mayfield, a master plumber working for Planet Plumbing & Drain in Boulder, Colorado, says in his work he encounters CPVC piping about 20 percent of the time. 

“It’s approved to put in houses, but I think it’s too brittle,” he says. “If it’s coming out of the floor and you kick it or anything, you have a good chance of breaking it.” 

He doesn’t use it for repiping and prefers copper, partly because of the craftsmanship involved in installing copper pipe. 

“I’m a 25-year plumber so I prefer to use copper. It actually takes a craftsman to put it in,” he says. “Not everybody can sweat copper pipe and make it look good and make it look right.” 

But as a less expensive alternative to copper that doesn’t carry some of the problems associated with CPVC, Mayfield, Grzetich and other plumbers say they often turn to PEX because it allows more leeway for expansion and contraction, and also carries a longer warranty than CPVC. For Mayfield and Grzetich it’s as much about the ease of installation as it is providing customers a product that is less likely to cause issues in the long term.

“A lot of it comes down to budget, yes, but also if you’re doing a repipe on a finished house where you have to cut the sheetrock and everything, it’s always easier just to do it in PEX because you can fish it through like an electrical wire,” Mayfield says. “It cuts the labor down for sure. 

“And CPVC uses glue joints that set up for a certain amount of time,” he adds. “With the PEX, you just cut it with a plastic cutter, expand it with a tool and put it over a fitting. It’s a lot less labor intensive as far as gluing and drilling holes. Gluing on CPVC, you have to glue every joint. Whereas PEX, you could probably run 30 or 40 feet of it through some holes and you don’t have any joints.” 

Any piping product will be susceptible to problems if it’s not installed properly, but Mayfield notes that CPVC has a smaller margin for error than PEX since it is a more rigid pipe that seems to get especially brittle over time. 

“If a plumber uses CPVC and is, say, off by half an inch on their holes, they’ll have to flex the pipe to get it in a hole,” he says. “It will be fine for many years and then suddenly, because of the strain, develop a crack or leak. Everything has to be really precise on the measurements with CPVC. Then it’s also a little nerve-wracking to work on because if you take an angle stop that’s screwed onto CPVC and you’re using two wrenches, you almost always flex the pipe a little bit. You’re always worried about breaking the pipe because it’s brittle.” 

Grzetich says he stopped using CPVC for repipes and turned to PEX about three years ago. 

“We did a house in a new subdivision — the house was only 6 years old — and we had to replumb the whole house because it was in CPVC. We actually ended up doing three other jobs in the same neighborhood. After that, the first repipe we did was in CPVC because we didn’t know what else to use. But then we looked into it and found a better product.” 

Grzetich uses a brand of PEX manufactured by Uponor. 

“I’ve done about 20 repipes with Uponor. I’ve had zero callbacks, zero issues,” he says. “I use it over copper usually. The only time I use copper is for stub-outs to make it look nice. Copper is still a very good product. It’s just expensive.

“I do know plumbers who still use CPVC. Some people just stick to their old guns and when something like Uponor comes out, they wait awhile before they start using it.” 

But according to Steve Forbes of Priority Plumbing in Dallas, Oregon, CPVC can still be a reliable material for a plumbing system as long as it’s installed properly. 

In a blog on his company’s website, Forbes writes about some of the concerns surrounding CPVC, noting that in his experience, CPVC pipe failures are related to improper installation and usually affect only hot-water lines. 

“CPVC will expand when heated, and if the system is installed that does not allow the hot-water lines to freely move when expanded, this can cause a joint to fail,” he says. “Each instance I have observed was because of an improperly designed/installed system.” 

According to CPVC pipe manufacturer Lubrizol, CPVC will expand about an inch for every 50 feet of length when subjected to a 50-degree temperature increase. Offsets or loops are important for long runs of pipe in order to accommodate that expansion. 

“I believe that the problem resides in that many plumbers installed CPVC just like copper, and did not allow for the added expansion and contraction of CPVC systems,” Forbes says in his blog. “If the piping is installed … with enough changes in direction and offsets, expansion and contraction is not a problem.” 

Forbes does acknowledge that CPVC can get brittle, and extra care should be taken when attempting to repair it. Still, he stands behind the product. 

“CPVC, if properly installed, is good and does not need to be replaced,” he says. “I repiped my own house with CPVC over 10 years ago — no problems.” 

More often than not though, PEX is becoming the material of choice. 

In his Southern California service area, Paul Rockwell of Rocksteady Plumbing says CPVC plumbing is rare. 

“Sometimes you see it in mobile homes or modular homes, but I can’t think of a foundation home that I’ve seen it in, in the 15 years I’ve been working here,” he says. “I don’t know why it’s not around here. We used a lot of it doing tract homes in Colorado in the 1990s when I was working there.” 

Copper and PEX are what Rockwell most often encounters in his work. He typically uses Uponor PEX on repiping jobs. 

“PEX is nice because you can snake it into places and you don’t have to open as many walls as you would with copper,” he says. “If somebody came to me and wanted to do a copper repipe, I’d do it but it would be 2 1/2 times the price of a PEX repipe just because of the material and the extra time. So it’s pretty rare that somebody asks for that.” 

In his limited experience working with CPVC, Rockwell says he has seen the same issues described by others. 

“The glue tends to take an especially long time to dry and I do mostly service work so the idea of repairing CPVC and waiting hours for the glue to dry isn’t very appealing,” he says. “And I’ve seen it get pretty brittle over time. I don’t have a huge amount of experience with it, but even if it were popular here, I think I would still use PEX over CPVC. As long as it’s installed properly, I haven’t seen any problems with it.”


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