CPVC vs. copper to plumb a house? How about PEX or PP-R?

A. I am interested in why you want to change from galvanised pipes to copper or CPVC "due to little water pressure". I cannot see how changing the pipes will alter the water pressure, unless the pipes are blocked with chalk or something.

Anyhow, firstly, CPVC is "chlorinated polyvinyl chloride" - it is a "polymer" or plastic and has greater heat resistance and better impact strength than conventional PVC. The manufacture of PVC entails using vinyl chloride monomer and this is highly toxic, but if the correct grade is bought, this will not be a problem. The best way to get the correct grade is to go to a reputable plumbers outlet and get it there. You will also be able to compare its price with copper pipe. Being in the UK, any comparison I can make will not be applicable in Georgia!

The advantages of CPVC over copper are varied, but unfortunately not precise. Firstly, CPVC will not corrode, as copper can do, secondly, it will not induce corrosion elsewhere, as copper can do. Thirdly, it is a pretty poor electrical conductor, so if you use your water pipes to earth your mains electrics, you may have a problem there. Fourthly, you can solder copper, but you can only join CPVC with special adhesives (obviously you can use special connectors for both types of pipe). Fifthly, you can paint copper pipes, but CPVC will not be so keen to take on most paints. I believe copper is better than CPVC at operating in extreme temperatures, but I suspect that is not a problem in Georgia. Sixthly, if you have hard water and want to soften it by electromagnetism, copper pipes are much better than CPVC as they will induce an electromagnetic field and CPVC will not. Seventhly (?!) copper pipes, if made properly, may have better resistance to some unwanted chemicals sometimes found in drinking water. Eighthly, copper is pretty good at reducing and preventing arthritis and small doses of copper salts are good for you. Finally, CPVC is more up to date than copper, but personally I think copper has got "class"!

At the end of the day, it is up to you and your taste. Either way, do not do any plumbing work on the cheap -- get the correct materials for the job and get them certified at the POS -- a cheap job can result in catastrophic failure and water everywhere!

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A. Hi Bellskye !

Re cost difference between copper and plastics, I haven't the slightest clue. Goest thou to thy nearest plumbing store and you'd find out.

Re PVC and CPVC. There is no difference except for price and CPVC's higher temperature resistance.

Certainly, PVC would be easier to install than copper and cost far less than CPVC.

PVC would, I feel, be ideal for all cold water lines. The standard pipe is approved for potable water. PVC or CPVC's disadvantages lie in being attacked by many solvents and cracking during a freeze-up (but Polyethylene can freeze up till the cows come home with impunity)

That PVC will leach out toxins is, hells bells, total nonsense. In schools rearing fish eggs, they all die, i.e., the hatchlings do, if the water is fed in using copper pipes. But not with PVC. Please draw your own conclusions.

Summary ... use PVC ... and if you go to the 'library' on finishing.com, there's an article on How to and How Not to cement PVC.

A. Use only CPVC for your hot and cold water supply lines. Go to www.flowguardgold.com/featuresBenefits/pipevscopper.asp^^{(ed. note Aug. 2013, that link is broken, try: www.lubrizol.com/CPVC/Resources/Understand-Differences-Copper-FlowGuard.html)} and read comparisons and you will arrive at only one choice, CPVC. I am not associated with Flowguard Gold. If you add pipe insulation on CPVC supply lines, be sure it is recommended by the manufacturer and compatible with CPVC. CPVC can be painted with latex paints only (no solvent or oil based paint products should be used). PVC is fine for waste pipes.

2004

Take a lesson, salespeople: "Damn your competition with faint praise" :-)

... because when a document touts itself as a point-by-point comparison between two alternatives, and finds huge advantage to their own system on fourteen (14) different points, and is utterly powerless to concede even one single slim advantage, on any count, to the very widely used alternate system, it condemns itself as being just silly sales blather.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. I am the Georgia Operations Manager for the largest Polybutylene remediation company in America. We offer both copper and CPVC. I will tell you that we have just a little bit better profit margin with copper but strongly suggest that people use CPVC as long as it is Flowguard Gold CPVC. Don't tempt yourself by mixing PVC and CPVC. CPVC is rated for both hot and cold, PVC is cold only, the outside diameter of the two are different so a wider variety of fittings will be necessary, the cements and applications are different, etc. I don't recommend the copper because of it's vulnerability to corrosion, (all water is corrosive to copper). The corrosion dissolves into your potable supply adding heavy metals like tin, antimony, of course copper as well as sulfites and sulphates. Flowguard Gold is quieter, will outlast the copper, and you don't have to use a torch in a finished home to install it.

Sorry, G, PVC gets like cooked spaghetti at high temperatures.

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PS: There are credible reports further below that claim that PVC is not a problem for domestic hot water lines. Apparently my recollection was faulty, and the "spaghetti" I saw was on waste lines which included steam condensate.

A. Ted, (et al)

Regarding PVC for hot water lines... WHO in their right mind keeps their hot water lines at or above 140° anyways?! Just because the water heater is capable of such a feat, does not suggest it to be a good idea... And I have yet to see a plain 'ol Sched 40 PVC pipe soften "like a spaghetti noodle" at 140° - the Vicat (softening) point of the stuff is over 180°... That's where the material BEGINS to soften, not where it becomes a noodle...

That said... If you are under 140° on your hot water runs - which you should be... Go for it. I installed it over a decade ago as a new homeowner that didn't know any better, and my lines haven't flailed, failed, or shown any signs of wear yet. Funny how ignorance sometimes disproves "common logic"...

My .02 - take it for what it's worth.

A. All these posts about PVC pipe for cold water and no one mentions the main problem with such. PVC will leach your water if it gets above 73 degrees Fahrenheit. It is a underground pipe only and temp limit should be plainly printed on the pipe.

A. I have worked for a major retailer selling all the three materials discussed here for some years. I have always been curious why CPVC didn't sell better than it does. Having read the posts on this topic let me take note that almost none of the posts here (with one exception) seem to come from people with much experience installing CPVC. I've researched this issue of copper vs. CPVC (from the manufacturers on down) for a while now. Seems there's only one logical reason CPVC was never widely accepted years ago when it was introduced: because it was plastic. As one state inspector concluded, it's really an issue of "perceived quality". An honest assessment should come up with the conclusion that there's nothing inherently wrong with CPVC and many advantages to it in fact. Sure, nothing prettier than a well laid out copper system, and yeah, it's stronger! But balanced against it's cost in material and time of installation, CPVC should win any contest along those lines. Whole buildings are being laid in with this stuff now that copper prices are crazy. Now, with respect to PEX (Polyethylene cross-linked): I think PEX is wonderful for its' flexibility only. PEX is no godsend with respect to cost, those brass fittings add up. To conclude, when strength is needed, or when you get close to a high temperature source like a flue, I'd suggest you stick to metal. If flexibility is critical, go PEX. If cost is important, and flexibility is not important than I say try CPVC and Flowguard gold glue, I think it's so ridiculously easy and fast you'll be converted.

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Ed. note: Your input is very welcome, Pat, but please refrain from challenging the credentials of the other posters; it derails the fun & pleasant technical conversation and introduces ad hominem sniping and flaming.

A. Living all but two of forty four years in Vermont, New Hampshire, Upstate NY and Alaska, 21 years on a farm, nine years in construction and the balance in the military, I can say from extensive experience that nearly everything busts in a hard freeze, copper, galvanized iron, PVC or cast iron all split and break. My first house was a trailer and I replaced everything with black plastic underground supply line and hose clamps, over the course of two winters because that was the only thing I found that would hold up. Saying copper is freeze resistant is a bit silly; maybe more than PVC, which shatters like china in the cold. I just re-plumbed my whole house with PEX for about $1000 in materials. Couldn't have touched that with copper. CPVC would have been even cheaper, but I didn't need to gut the sheetrock and plaster to run the lines either. I've heard that PEX is more freeze resistant than others, but I'm hoping not to test the theory. It's the easiest thing I've ever used though, and I've sweated quite a bit of copper and glued a lot of PVC for a non-plumber.

A. I work in a plant house of a hospital.These days we are planning to replace the copper pipes to CPVC. According to my survey, I found CPVC better than all metals and PPR (polypropylene random copolymer). it can handle a temperature of more than 95° C. and a pressure of more than 16 bar. It is more healthy than other materials. Furthermore, it easy to install. Just go through available manuals and select the right one.
ALL THE BEST.

A. A properly soldered copper pipe joint will last a lifetime. With a number of years, CPVC joint can let go, even tho they worked fine for a number of years. The temperature is no problem for true CPVC.

A. PPR is far better than CPVC & Copper. Main reason is the positive argument state for CPVC is equivalent to PPR and a few more advantages than CPVC can be listed. Thanks & best wishes...

A. CPVC is not affected by sunlight to get deformed whereas PPR is.

A. I just spent hours replacing a broken CPVC pipe in a wall. If they had used copper, this would not have happened. I will NEVER again use CPVC in any place where it cannot be conveniently accessed or repaired. Ripping out a wall to fix a broken plastic pipe is not fun!

A. CPVC is THE best. For cost and ease of installation nothing is better. I removed all the old galvanized pipe from my house and re-installed both PVC and CPVC for the cold and hot lines. Now I did have access so I could bring it up into the walls to the Kitchen and both Baths and the W/D hookups.

The re-install of about a total of 120 feet of pipe was done in about 3 hours. Using PVC/CPVC is SOOOO easy to cut, stick in "tees" for offshoots and cement together. And NOT ONE LEAK.

My house now has copper and I have NO desire to learn to deal with soldering, especially under the house in the crawlspace where I have insulation galore. CPVC will be ALL I'd ever use.

A. Hey CPVC might have benefits but what about the raw material used in its production. CPVC is made of crude oil, by use of CPVC aren't we taking a step back on the new world order to go green and save the planet.

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Ed. note: We thought that is what everyone just finished doing, cousin :-)
Can you please try to frame your question in terms of the responses that were already offered? Thanks.

A. In California the reason we use copper is the unions have fought plastic for decades. The reason being is that plastic is much easier to install and there is less follow up issues for a plumber to deal with (therefore less work for the union). The unions' argument is that the solvents used to put the pipe together are too dangerous for the installer. Like using a torch with melting metal isn't? In my area there are currently a number of lawsuits regarding pin hole leaks in copper pipe by large home builders against the water districts based on some perception that the water isn't properly treated. The reality is there would be no issue with plastic.
Only in the last several years can you get a waiver to plastic for "hot soil".

A. PVC vs CPVC? For hot waterlines, ALWAYS CPVC. If you have your home repiped, it should ALWAYS be permitted and inspected. NO EXCUSES. Furthermore, if an inspector sees PVC in a hot water run, regardless of water temperature, you get to see the wonderful RED TAG and get to listen to that inspector mumbling under his breath about the installers lack of NATIONAL PLUMBING CODE KNOWLEDGE. In Fl, the soil is slightly alkaline. Add that to the high mineral content, and oxidizing effects of chlorimines, copper should really only be used in exposed areas, and ONLY IN TYPE L COPPER. On gas water heaters, copper should be used for at least the first 18", 12" for electric. In the 20 years I've been in plumbing, I have seen around 30 or so CPVC failures. Compare that to the 400 plus copper failures that my company repiped with CPVC just last year.

A. Anyone who has a choice between copper and PVC piping needs to have their head examined if they use PVC. Unions or not copper piping does not normally break at coupling joints like PVC does and PVC does NOT stand up to hot water!! If you want to have leaks and water damage in your house use PVC, CPVC or anything other than copper. Take it from a home owner of an 11 year old house plumbed with PVC who now needs a $50,000 re-do, this stuff sucks. P.S.: homeowners insurance does not pay to mitigate the mold that you will get from the leak before it is detected. So, much of that damage will be out of your pocket.
GOOD LUCK.

PLASTIC PIPE SUCKS.

A. I suppose the real answer is based on various factors. Some areas, like surface water systems, copper lasts a long time. CPVC works where you can't use copper. Heck, if I had my way (being a 60 yr. old master plumber), I'd use threaded bronze. Now that!!

A. Hi Tamim. It may have to do with the temperature of the sewerage, or strength of steel pipe, earthquake resistance, fire resistance, or a need for electrical conductivity for some reason. I don't think anybody can make worthwhile guesses why a 3rd party has specified something. Good luck.

Regards,