The finishing.com Hotline: Serious Education ... plus the most fun you can have in metal finishing. Ted Mooney, Webmaster
CPVC vs. copper to plumb a house? How about PEX or PP-R?
Q. I am an artist and my husband is a residential designer. We have galvanized pipes now and are going to replace them, due to little water pressure. What is safest, copper or CPVC (chlorinated poly vinyl chloride) for plumbing a house? I read that PVC will leach toxins. How is PVC different from CPVC and what might be the advantages over copper. How do they differ in price?
artist - College Park, Georgia
Copper pipe (courtesy madeinchina.com) - PVC pipe (courtesy prettyhandygirl.com) - CPVC pipe (courtesy Flow Guard) - PEX pipe (courtesy pex-plumbing.org) - PPR pipe (courtesy extruder.com.cn)
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!
R&D practical scientist
Chesham, Bucks, UK
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.
White Rock, British Columbia, Canada
(It is our sad duty to advise that Freeman passed away April 21, 2012. R.I.P. old friend).
Plumbing for Dummies
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.
- Sarasota, Florida
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. RET
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 sulfates. Flowguard Gold is quieter, will outlast the copper, and you don't have to use a torch in a finished home to install it.Gary Andrews
- Lawrenceville, Georgia
PVC for Hot Water?(2007)
Q. I JUST INSTALLED PVC FOR MY HOT WATERLINES. AM I IN TROUBLE?G BOONE
HOMEOWNER - DAYTONA, Florida
Sorry, G, PVC gets like cooked spaghetti at high temperatures.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
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.
July 6, 2009
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.
- Hastings, Michigan
August 13, 2009
I would have to agree with M., I too have used PVC for both hot and cold, many times. I have had the same positives and also have had the split to the end if left to freeze. But I have had the same happen to copper and it cost a lot less to replace the plastic. As far as soft noodles... never seen it. May be worth a try though.Jeff Homeman
- Clinton, Oklahoma
February 19, 2011
I agree with M. Smith. I'm sure there are many industrial and business settings that require pipes capable of carrying near-boiling water, but not the average house.
If you're installing pipes for fire sprinklers, though, please don't use PVC:
- Campbell River, BC, Canada
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.Raymond Haywood
- Tallassee, Alabama
March 15, 2008
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.Pat McSherry
- Minneapolis, Minnesota
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.
April 27, 2008
Q. CPVC fittings? I am adding to and moving an install of CPVC, hot and cold runs... have found all the fittings I need except one and it says on the box, COLD water only. What's up with that?Paul Williams
hobbyist - Macon, Georgia
What pipes won't burst in freezing weather?May 17, 2008
Q. Not often, but every now and then we get temps below freezing. Will CPVC burst? Thanks.Scott Darrn
- Tuscan, Arizona
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.Julian Benoit
- Black River, New York, USA
June 10, 2008
Q. I am in the process of making a decision about what material to use to re-plumb my house, originally built in 1956 in Central Florida. The more I read, the more confused I become. Not a big fan of plastics, I thought copper would be the best option but have been told by a plumber about major issues with the quality of water in the area and lightning causing pin holes. Does anyone have any knowledge and/or experience in Central Florida?Sandra L.
- Orlando, Florida
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.
- Manama , Bahrain
April 28, 2009
Q. My husband and I are renovating a house built in 1894 in Ohio. To stay current with green initiatives, we would like to install an on-demand water heater, and would like advice on pairing the heater with CPVC plumbing. Are there inherent risks to the piping being subject to the temperature of the water exiting the heater?Sue Buck
Homeowner/ builder - Columbus, Ohio
May 15, 2009
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.James Watts
- Navarre, Florida
December 14, 2008
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...Godly P.S.
plumber - Manama, Bahrain
November 8, 2009
A. CPVC is not affected by sunlight to get deformed whereas PPR is.zuhair hasan
February 8, 2010
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!Matthew Reed
- Lebanon, Oregon
April 23, 2010
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.
- Portland, Oregon
August 4, 2010
Q. It appears there a lots of fans for CPVC. So why do most new houses (around south Texas at least) use copper? I would think they would go for the least costly option if there are no advantages to the more expensive option.P Morris
- Houston, Texas, USA
December 7, 2010
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.Inderjit Singh
August 8, 2011
Q. Hi maybe you can help me out I am building a house in Miami Florida and I would like to know the pros and cons of copper vs CPVC, and what you would recommend and why.Javier Torres
home owner - Miami, Florida
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.
December 30, 2011
We have been having a terrible time using CPVC for hot & cold water piping inside our house built with brick and r.c.c (no wood). First incident we had was that a leak under a floor developed after about 5 years of use. Then the CPVC pipe melted where it connected to the hot water heater when the thermostat failed. After fixing all this we find another leak developed when the weather gets cold. My conclusion is that CPVC is unsuitable for brick and concrete structures where there is little scope for expansion ? Definitely not suitable for connecting near a boiler or hot water.Rajiv Ghai
- New Delhi, India
January 5, 2012
! Every hot water heater installation manual clearly shows copper at exit for a required distance. I would suggest ten feet of copper, then convert to CPVC.Andrew Lehrer
- Tampa, Florida
January 20, 2012
Q. CPVC in large sizes (1 1/2" up to 3 1/2" or 4") for replacement of copper in a high-rise apartment setting (13 stories)? With cost being a factor in materials as well as with labor, we are looking to replace the copper mains and tees up to couplings where we want to change back into copper and clamp (Verisa) the transition pieces to brass ball valves and then into the existing copper before the copper lines go into the utility chases up to the top floors. We plan to assemble the new CPVC main feeder lines along side of (above) the existing copper and once hung in place shut the water off and change out as many as possible each day once the water is off. It will be off from 9 AM through 3 PM each day until we have changed out the forty-two valves in the first floor ceiling system. Is there a commercial plumber out there who would agree with this application?Forest Hall
Sr. Project Manager - Memphis, Tennessee, USA
February 25, 2012
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".
- Trabucco Canyon, California USA
What about PEX?March 1, 2012
Q. How about PEX? I have been using CPVC and find it fairly easy to use, but I am planning on running a line from the main house to an outbuilding, and am leaning toward using PEX this time around. From what I can tell, it is far easier in existing installations, less prone to freezing/splitting, and can handle hot and cold without problems.
My biggest problem thus far is the cost of fittings and the crimping tools, but these are outweighed by the ease of install and the freezing threshold.
I am also getting weary of the constant battle between PVC/CPVC, which need (or can't have) primer, a certain glue color, etc. Even when you follow the instructions, some home or building inspector or salesperson swears that you have to do it one way or the other, and these directions often conflict with the printed materials.
Any contrary opinions out there? Any suggestion on the use of PEX? Helpful hints, tips, suggestion will be graciously received.
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.Jay Peterson
20 years in plumbing - Tampa, Florida, USA
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.
PLASTIC PIPE SUCKS.
- Hillsboro, Oregon, USA
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!!Richard Wysham
- Paradise, California, USA
August 9, 2012
Q. Under my kitchen sink, I have metal pipes now, and one just sprung a leak. I need to replace most of the set-up including the "u"" pipe. I have read about these three different materials to use and am totally confused. Can someone help me decide what to use?
- Evergreen Park, Illinois United States
September 18, 2012
Q. Clearly, there is no right answer but if I live in Atlanta, GA is it okay to use PVC for my water service line in from the street?Lauren Head
- Atlanta, Georgia
October 1, 2012
Q. Okay. The gist I get is PVC, CPVC, Copper and PEX are all okay in a residential home ... but use copper the first 18 inches from the water heater in Florida.
Thanks for all of the posts.
Now, I'm about to have my entire house re-run.
The plumber, who seems like a great guy, plans to use CPVC Flow Guard Gold with glue-on stops (not compression stops).
He said for $1,500 more (30%) he could do PEX if I wanted. That was only after we chatted about it. Not an up-sell.
He thinks CPVC has a 15 to 20 year life. Whereas PEX is warranted for 25 years.
My gut, based on this forum is to go with CPVC.
However, he mentioned 1 year warranty on his install but it doesn't cover split. Then I see a CPVC joint or whatever split on the web :-(
The Plumber is comfortable installing PEX and says he has the proper equipment.
If it were your house what would you do? I'm comfortable either way. Don't want to spend a dime more than I have to.
My house was built 1998/1999. Soft copper. So CPVC Flowguard for $5k? or PEX for $6.5K?
My husband HATES plumbing so you will always have a job at my house!
I just don't want to install something and have a leak.
Thanks a bunch. My husband comes home later today ... and If you think PEX, I'll talk to him. Otherwise I'll not bother him.
- Ocala, Florida, US
June 7, 2015
Q. Why are we using Hot dip galvanized for sewage line instead of PVC?
Albawani - KSA , riyadh
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.
Ted Mooney, P.E. RET
Pine Beach, New Jersey