Copper vs Plastic

Reply

  #1  
Old 07-10-03, 08:52 PM
Liquid plumber
Visiting Guest
Posts: n/a
Question Copper vs Plastic

After working with both CPVC and soldered copper, there is no doubt in my mind that a joint on the former is much more reliable and much less likely to leak than a joint on the latter. This makes my wonder why CPVC didn't displace soldered copper a long time ago. I know several people who have plumbed all or part of their houses with CPVC and none of them have ever had any problems with their CPVC plumbing.

I have also come to suspect that CPVC female threaded adapters are not as susceptible to cracking as most plumbers have been led to believe. If I had to make a guess, I would have to say that most of the cracking problems result from the fact that many people (especially amateur plumbers like myself) treat female CPVC adapters like galvanized pipe and use Teflon tape and a pipe wrench when threading them. If people just screwed them on hand tight without applying anything to the threads, I would be willing to bet that CPVC female adapters would be no more likely to crack than any other kind of adapter.

Even though I don't know much about PEX just yet, I have often wondered if PEX joints put together with compression fittings are as reliable as the joints put together using the crimp tool.

Robert
 
Sponsored Links
  #2  
Old 07-11-03, 03:19 AM
Mike Swearingen's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 1999
Location: Northeastern NC On The Albemarle Sound
Posts: 10,952
Received 0 Votes on 0 Posts
Cool

CPVC is certainly easier to install and repair than copper.
All threaded fittings need to be taped or pipe doped and snugged with a wrench. Hand-tightening only is asking for leaks. Over-tightening any plastic threaded fittings can cause them crack, of course.
Compression fittings are the more likely to leak, however, than any other type of fitting, although they can last for years.
 
  #3  
Old 07-11-03, 05:49 AM
notuboo's Avatar
Member
Join Date: Sep 2001
Location: Kansas City MO
Posts: 1,780
Received 0 Votes on 0 Posts
Cpvc has it's uses as does Copper. Cpvc does not have the history that copper pipe has. Copper can and has lasted well over 50 years in many applications. Cpvc still has a while to go to see if it can still maintain it's integrative over many, many years of service.
Low levels of chemical exposure from treated tap water may take years for a problem to show up. When PVC (original version) was introduced, enginners designed uses for it that cost big bucks to fix after it was determined there was a problem. Pvc is fairly stable now, but long term will tell.
 
  #4  
Old 07-11-03, 06:43 AM
Plumber2000's Avatar
Member
Join Date: May 2000
Location: Eugene, Oregon
Posts: 5,841
Received 0 Votes on 0 Posts
Cpvc will leave a odd taste in the water, was told it will go away thou
 
  #5  
Old 07-11-03, 09:44 AM
D
Member
Join Date: May 2003
Location: Mid-Michigan
Posts: 5
Received 0 Votes on 0 Posts
I felt compelled to contribute here, as I've just completed converting half (cold supply) of my plumbing to cpvc, and running a dedicated line from my well tank to my outside faucet.

My house is about 12 years old, I bought it in 2000. Last year I had a cistern installed due to intolerable well water (tons of iron, sulfur stink, salt), even with a softener, which I got rid of after the cistern went in (didn't want to deal with filters and pressure loss issues assoc. w/filtering). Instantly, the city water from the cistern made life much better. But I knew the buildup inside my copper pipes was still causing problems for the water, and every joint on the cold supply was coated in green and white deposits, so it was time to replace them from the tank to the fixtures. The piping beyond the water heater is ok for now, not nearly as bad as everything else.

I didn't know much about cpvc, but I had never soldered copper, either, so I just chose cpvc. I like the latest "technology", as many do, copper just seemed obsolete for me. I was concerned about the fact that the joints are just glued together...would they hold? At first, I ran about 12ft of line, which included a water meter and 4 joints, and then just compression fitted it to the existing copper. Not realizing that the cure time is at least 2 hours, I pressurized the system after about 10 minutes...I did hear some creaking in the joints, and I think one of them did push out about a 16th of an inch, but there were no leaks!

Before continuing, I did a little research, and found the correct curing times, no worries since. The glue states that it's not absolutely necessary to clean the joints before priming them, but I have lightly sanded both surfaces, used cleaner, primer and cpvc glue on all of my joints, everything is holding up nicely. As far as strength goes, I am really amazed at how strong the joints are. No concerns, those joints cure so well that there is no way anything could pull them apart. I'm positive that the pipe or fitting would break before the bond would fail, like a good weld.

As far as the supplies up through the walls (1/2"), most of them are secured inside the walls, so I used compression fittings just below the floor to connect the cpvc to the copper, rather than trying to pull the copper out. I periodically check them, and give them a tug, but they seem pretty solid, no drips from any of them. I may replace them with sweated cpvc to copper unions, but we'll see.

As far as the latest new run to the outside faucet, I picked up a new sill"faucet" with male copper threads, and found a cpvc to copper union with female threads. Using Teflon tape, I threaded the union onto the back end of the faucet (both metal), and ran my cpvc right from there. I've never seen that done before, so I'm pretty proud of that one. The faucet has a 10" pipe, so the union is plenty far inside the basement to prevent freezing issues.

I certainly didn't intend to compose a novel here, but I figured I'd share my experiences with cpvc, as it tends to get a bad rap from die hard copper fans. I don't plan on ever installing copper, but I would like to learn copper soldering, as I'm sure I'll have to do some at some point for repairs. CPVC gets two thumbs up from me.

On a side note, a couple of things I've learned while working with the stuff. It's difficult to test fit perfectly, as the fittings don't dry fit too well, and its hard to get them apart for gluing if you force them together while test fitting. My solution is just to cut a little long, once they fully seat with the glue, the length is usually perfect. I also did use female threaded fittings (cpvc) at the water meter. Although I did tape the threads, I don't think it is really necessary on them, they have a rubber washer in them that actually seals the joint. As far as over tightening them, I can see how it happens, but they're strong enough as long as you are careful. I might avoid them if possible, just for peace of mind.

Hope this helps someone out there looking at a similar project.

-Derek
 
  #6  
Old 07-11-03, 10:24 AM
Mike Swearingen's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 1999
Location: Northeastern NC On The Albemarle Sound
Posts: 10,952
Received 0 Votes on 0 Posts
Cool

Great information, Derek!
Thanks for your help.
Now your info will be able to be accessed through Search above, too.
Mike
 
  #7  
Old 07-11-03, 09:29 PM
Plumbrich
Visiting Guest
Posts: n/a
In the last 5 years i have found alot of pvc drain pipe falling apart.Most of these are in the 20 to 25 year range.Will cpvc do this 20 or so years from now? I dont know I do know some negatives.Cold weather and cpv dont mix.Copper lines freeze also but you can thaw them out easy.When they do burst you get a spray and cut out a small portion.Cpvc cracks and burst in long runs. More pipe to replace and 10 times more water damage.When you have copper pipe and your prv goes bad and pressure jumps to 140psi you notice more water at the tap.When this happens with cpvc you notice more water flooding the house.Cpvc and a stuck thermastate on a water heater dont mix.Example 4 months ago customer had thermostate stick and heat water to the point of the relief vavle discharging cpvc came apart in three places flooding scalding water in finished basement.Cpvc secured to tight causes creaking when pipe expands and contracts creates stress points to fail.Cpvc secured to loosly causes pipe to flex to much and fail over time.Sunlight causes it to get brittle over time.I could go on and on.I could also tell some bad points of copper but not as many.Most problems with copper (not all) is incorrect instalation.I think the biggest problem with cpvc is about 70% of what i see is improperly installed even by so called plumbing co.I used to never see a copper pipe connected to galv or water heater without a dilectric union now i see it 5 times a day.This is your main reason copper fails it couses pin holes to appear in line most times far away from the jont.
 
  #8  
Old 07-13-03, 10:53 PM
Ragnar's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2002
Location: Albuquerque
Posts: 1,349
Received 0 Votes on 0 Posts
One of my favorite subjects...

First, there are only 2 reasons I ever run CPVC, cost (laborwise) or because the house is on a well...

CPVC is far easier to put in obviously... and it IS very reliable and has been around quite a while in the north... (I have heard 20+ years, but I am not sure on that number)... However, it is not structurally as sound as copper... Meaning, that in certain instances, I usually have to convert from cpvc to copper even on a cpvc job... For instance, on a tub valve where I need to strap the valve in good and tight... On the shower riser in particular, it is simply inadequate to run it in cpvc... Even though you can support it well enough to screw in the initial shower arm, it will never be as sturdy as a copper riser, and it will often leak or break if you have to reinstall the shower arm for some reason... Also, code in my area requires and 18" lead of copper or galvanized off the top of a gas water heater, since cpvc dries out and gets brittle when exposed to external heat as in a flu vent... Outside faucets are hard to make secure if run with cpvc also... As for transitions, I realize that some cpvc female adapters are made with rubber washers and are designed to be hand tight, as are some unions... Most plumbers looks at a joint made up with a washer as a "temporary" joint... One that might be taken loose relatively often, as on a garden hose, or on a union to some mechanical device like a PRV... I don't like having them in the middle of a permanent water piping run... They do, however, make a cpvc threaded transition that is brass female on one side and cpvc glue hub on the other and they work perfectly well and can be tightened with wrenches to an appropriate degree... Plastic has one other disadvantage in my opinion... It makes more racket... You can strap cpvc on EVERY stud and joist, and it will still have give and movement that copper will never have...

And for the original poster who says that a joint on CPVC is more reliable and less likely to break than a copper joint, I would have to whole-heartedly disagree with you... while CPVC does make a dependable joint, they are prone to having leaks form months after installation if they are not installed properly, and certain brands of CPVC can get VERY brittle after a few months of being exposed to open air... If copper is soldered correctly, you can pressurize it instantly without concern for leaks and the joint can last for 60 years... CPVC can't make that claim... And as for thinking something is better because it is easier to put together, I disagree with that too... I use CPVC because it is cheaper to install for those that need to save money, or on well systems where the "hard" water eats away at copper, NOT because it is better... I work in homes in Atlanta pretty often that are extremely high-caliber homes, and they NEVER, EVER go with CPVC... It simply isn't done, because when the money is there, COPPER is a far more reliable choice....

As for gluing CPVC, you really shouldn't have to have primer... If you use the yellow can of glue as opposed to the orange, it is designed to be used without primer... It is simpler than the two-step process, and I most often pressurize a recently installed system about 15 minutes after the final joint has been installed, and it never blows loose... It would be great to let it "cure" fully, but it is not often practical...

As for PEX, I hate the stuff as much as I hated poly, but like poly, crimped fittings are far more dependable than mechanical ones... But frankly, I wouldn't install either one for my worst enemy....
 
  #9  
Old 07-14-03, 11:00 AM
D
Member
Join Date: May 2003
Location: Mid-Michigan
Posts: 5
Received 0 Votes on 0 Posts
Ok, at first I wasn't going to touch this thread anymore, but I think we can keep this "discussion" civilized.

I can agree with many of the points made here, and I can see where both sides are coming from on most issues.

Although I plan on leaving the short runs up though the wall as copper in my current house, I'd probably want cpvc inside the walls of a house if I were having it built. My theory is that copper will get pin holes inside the wall before a cpvc joint or run will fail. Even though the later is a bigger mess, I'd say it's less likely. The problem is making the stub-out rigid, the pipes can't be anchored solidly due to their need to expand, so I see a minor problem there (solved once the supply lines are hooked up). My main concern would be to get a contractor that does a lot of cpvc installs, not easy.

As far as shower risers, I'd agree that the elbow at the top should not be plastic. I'm thinking that's the part that anchors to a cross member (has a flange on each side), that whole thing should be metal, as should anything else structural. I'd use cpvc between them, or at least up to the valve.

Copper definitely has its place near the water heater, in my opinion. When I replace mine, I'll probably use those flexible copper runs (~24" long) with female fittings at each end (now we'll see who hates those). And, due to code (as Ragnar mentioned) and the obvious potential problems stemming from heat and fumes, I'll run copper up beyond the flu before switching to cpvc. I won't forget the dielectric unions, either, as I think was done on my current setup...

I also wanted to mention that the unions I've used are the type requiring wrenches (brass female w/cpvc hub). My outside faucet has large lag screws in its flange keeping it nicely rigid, and the pipes just inside are supported around the union. I saw those hand tighten unions, they look like a playskool toy, quite laughable, something I'd certainly stay away from.

I never really had a problem with copper until I got my house. While most of the system was 11 yrs old, part was only 2, and was in terrible condition. 1 of the 2 years was with a water softener, which helped the water, but the pipes just got worse. My house was moved to its current location in 2000, which was the reason a portion was newer. I'm thinking that most of the destruction started then (terrible well water, 147' down into pure iron/salt water). The stuff (piping I removed) was so nasty to handle, too, that just made me dislike it that much more.

I am concerned about problems with the water heater, one of these days I need to pick up a new pressure relief valve (just in case it doesn't shut off) so I can test my current one. I'd say a supply line to the sink or toilet would probably let go before a main fitting, but you never know. Wouldn't a properly functioning pressure relief valve also open if a pressure reducing valve malfunctioned? Either way, if I didn't have a cistern or well (which both normally have pressure gages), I'd want a gage at the main entry to keep an eye on things.

Lots of good points so far in the thread, I think everyone should asses their own needs and just go with what works for them.

-Derek
 
  #10  
Old 07-14-03, 01:04 PM
Plumber2000's Avatar
Member
Join Date: May 2000
Location: Eugene, Oregon
Posts: 5,841
Received 0 Votes on 0 Posts
When you stub out for the fixtures you can use brass female drop ear 90's x cpvc adapter's

and then use brass nipples out the walls, mount the drop ear 90's to blocks for a secure fit, this adapter can also be used on the shower riser.

I never had problems securing cpvc pipe, and have and will run cpvc on the shower riser.
 
  #11  
Old 07-14-03, 06:51 PM
Liquid plumber
Visiting Guest
Posts: n/a
Originally posted by Ragnar
One of my favorite subjects...

As for PEX, I hate the stuff as much as I hated poly, but like poly, crimped fittings are far more dependable than mechanical ones... But frankly, I wouldn't install either one for my worst enemy....
But would you make your worst enemy sweat copper?

I was reading the book "Do your own plumbing" and, according to them, many labor unions have lobbied local governments to ban plastic pipe because it's installation is so much less labor intensive than soldered copper. Of course, I wouldn't blame any local government for banning PB.

I wasn't too surprised when I heard that PEX is much more ubiquitous in Europe than it is here in America. But I was a little surprised to learn that Europeans have been using PEX ever since the 1970s. Apparently, PEX is not really new - it's just new to us. This made my wonder why we Americans decided to start using PB while they skipped PB and went straight for PEX. Did the European plumbing industry know something that we didn't?

Robert
 
  #12  
Old 07-15-03, 08:38 AM
D
Member
Join Date: May 2003
Location: Mid-Michigan
Posts: 5
Received 0 Votes on 0 Posts
Now that fitting looks like a good solution. It isn't easy to find that kind of stuff around here, however. We've got 2 HD's, 2 Lowes and several small plumbing stores in the area, but few cpvc to copper/supply line valve items available at any of them. I had a heck of a time finding 1/4 turn valves with cpvc couplings built into them. More stores are carrying them now, but I wouldn't even need them if I used brass stubouts from that elbow. What's the best way to go there, just a brass nipple with male threads on each end, then a female threaded supply valve? Being that the threaded fitting is inside the wall, is teflon tape or TFE paste a better way to go?

thanks.
 
  #13  
Old 07-15-03, 11:28 AM
Plumber2000's Avatar
Member
Join Date: May 2000
Location: Eugene, Oregon
Posts: 5,841
Received 0 Votes on 0 Posts
Brass nipple and screw on the female shut off valves, use pipe dope on the threads.
 
  #14  
Old 07-22-03, 04:50 PM
Kray
Visiting Guest
Posts: n/a
This thread was very informative to me as a do-it-yourselfer working on a new bathroom installation. I would like to add a couple of comments and maybe a question or two regarding my own experience.

I am using CPVC because of ease of installation. Cost was really not an issue because this is a small, one-time installation. I read up on CPVC on the internet (forums like this) and do-it-yourself books, and became comfortable that CPVC was the way to go for me.

I started having doubts when I went out shopping for CPVC pipes and fittings in my area (Northern California, near San Francisco). I found that most of the usual stores (e.g., Home Depot) do not carry CPVC. The staff at Home Depot and Ace Hardware had never heard of CPVC. I finally found one plumbing supply store that carried CPVC. They did not have everything I needed, but sold me what they had although a rude sales person tried to talk me into copper and said he would never put "that crap" (meaning CPVC) in his own house. (I concluded that this store deals with a lot of licensed plumbers and shares the plumbers' dislike of CPVC because its ease of installation for do-it-yourselfers takes work away from them.) I never did find certain items such as chrome shut-off valves with CPVC hub for gluing and wound up ordering them over the internet from a plumbing supply company in Pennsylvania.

My project is not finished yet, so I cannot say much about the final result. I've finished the rough plumbing with CPVC and feel pretty good about it. However, I am left with lingering concerns after learning that fittings are hard to find in my area, supposedly knowledgable workers in the stores are not familiar with CPVC, and it apparently is not widely used in my area. If anyone cares to add further comments to this thread, I guess my questions would be for assurance that CPVC is "OK" (although obviously not preferred by some) and also, whether anyone can comment on the extent to which CPVC is used in the U.S., whether it is more prevalent in some areas that others, and whether there is an explanation for it apparently being relatively unknown in San Francisco area? Thanks.
 
  #15  
Old 07-22-03, 05:24 PM
Ragnar's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2002
Location: Albuquerque
Posts: 1,349
Received 0 Votes on 0 Posts
Well, I do plumbing for a living and I use CPVC all the time... I really trust it, but I try to give the pros and cons of both copper and CPVC in this thread... CPVC will not deteriorate with muni water and the joints are VERY dependable... It is simply harder to support and as you found, it is hard to find good transition fittings that have brass on one side and glue hub on the other... Copper is definitely good for support and it will last DECADES if done right... It is obviously harder to install, but if done well, it does not fail early as some might think... It will, however, wear thin with well water prematurely and you should not use it unless you have a very good water filtration/softener system... You made the right choice with CPVC...

Certain areas do use CPVC more than others, but I don't know of anywhere that CPVC doesn't meet code... It has been around in Northern states the longest apparently but we have used it in the south for quite some time...

Oh yeah, one more thing... Plumbers may not like CPVC, but I GUARANTEE it is not because DIY'ers will take our work... DIY'ers create as much work as they do... Some of us plumber types just sincerely don't want to see people install junk out of not knowing better... I personally like CPVC but there are plenty of other products out there that HD and LOWES sell that I wouldn't want to see anyone install and it isn't because I lose the work... Just FYI... I didn't get offended or anything... I was just offering the view from the other side... ....
 
  #16  
Old 07-24-03, 07:19 PM
Liquid plumber
Visiting Guest
Posts: n/a
Originally posted by Kray
I started having doubts when I went out shopping for CPVC pipes and fittings in my area (Northern California, near San Francisco). I found that most of the usual stores (e.g., Home Depot) do not carry CPVC. The staff at Home Depot and Ace Hardware had never heard of CPVC.
I'm surprised that these stores were so unfamiliar with CPVC. It may in fact be the case that CPVC is less ubiquitous in California than it is elsewhere. As hard to believe as it may sound, CPVC is not as 'politically correct' as other kinds of plumbing. Even though the CPVC pipe itself is safe, the manufacture of both PVC and CPVC generate certain toxic byproducts that not all environmentalists are happy with. This may partly explain why CPVC is not very popular in California. But even those who are diehard treehuggers can still use PEX if they don't want to mess with copper.

I like that female drop ear pictured above. Now if I could only get my local hardware store to carry things like that. I've also wondered what kind of drop ears are made for PEX.

Robert
 
  #17  
Old 07-27-03, 06:42 PM
green jacket's Avatar
Member
Join Date: Sep 2000
Location: Williamsport and Blue Bell, Pennsylvania
Posts: 502
Received 0 Votes on 0 Posts
I find this topic a excellent one, I have a current project, to replace about 30' of copper. If I ever redo a significant portion of the plumbing, I think I may consider the CPVC because of well water. Materials purchsed, will install this coming week. In the Philadelphia region, I believe CPVC is readily available.
I have volunteered at a local chapter of Habitat for Humantity, and noticed in their most recent project, they used small diameter tubing that is red or blue, and each fixture has a dedicated line leading back to a central shutoff station. The connections were done with a strap of some type, I want to know if this is what is considered PEX. (I remember Lowe's stocked PEX several years ago)
What is the key problem with PEX? (Ragnar, comment?)


gj
 
  #18  
Old 07-27-03, 06:53 PM
Plumber2000's Avatar
Member
Join Date: May 2000
Location: Eugene, Oregon
Posts: 5,841
Received 0 Votes on 0 Posts
It's called PEX

Pex is said to have memory to it, as to, if it freezes and thaws out, it will return back to it original shape, and said to have a 25 year warranty.

I don't install it myself, the real outcome is not yet know, and only time will tell what it is really going to be like.

Take Orangeburg sewer pipe, if was the best product when it came out, look what happens to it over the long period of time.
 
  #19  
Old 07-27-03, 08:51 PM
Liquid plumber
Visiting Guest
Posts: n/a
Hasn't PEX been used in Europe since the 1970s? What kind of experence have they had with it?

Robert
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: