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what is the downside to cpvc?

Posted by mtobias1 (My Page) on
Wed, Mar 15, 06 at 18:11

I know it must be cheaper since the plumber has startedusing it for the supply and waste.


Follow-Up Postings:

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RE: what is the downside to cpvc?

It is quite inexpensive compared to copper. I don't know of much in the way of a downside. The only thing I can think of is you can't sweat apart a fitting when making changes. But then that's no big deal since cutting and fitting a modification is quite simple.


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RE: what is the downside to cpvc?

No downsides when comparing it to copper. Now pex; we can chat.


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RE: what is the downside to cpvc?

CPVC for the waste piping system? Tell us more about that! Who is doing that and where are they getting the proper size pipe? CPVC expands and contracts more with temperature changes than most other plumbing materials. If the installer knows and accomodates this movement with the design and installation, things will be fine. If the installer tries to strap the pipe down tightly to inhibit the movement, problems are assured.


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RE: what is the downside to cpvc?

As Busdriver has already pointed out, CPVC may not be used for Drain, Waste & Vent systems. Even if they could get the CPVC pipe in the proper sizes, there are no DWV rated CPVC fittings and the codes prohibit glueing dissimilar pipe and fittings together.

When plastic pipe is desired for the DWV system the choices are ABS pipe or Sched. 40 PVC (Some local jurisdictions will permit sched 30 PVC).
"But what exactly is CPVC?


To answer your question, CPVC is Chlorinated Poly-vinyl Chloride. You can think of this in terms of a second generation of PVC pipe inwhich the chemical formula of the pipe was altered slightly to overcome some of the problems that were associated to PVC pipe.

CPVC pipe is made in two dimension standards:
Although very seldom used, CPVC and fittings are available in the ASTM Pipe Schedule dimension standard, which means the pipe and fittings are exactly the same dimensions as thier PVC counterpart.

The CPVC most often used for residential plumbing systems is made to the ASTM "CTS" (Copper tubing Standard) and the physical dimensions of the material is the same as copper pipe.

Like everything else in this world CPVC has its good points and bad.

ON THE GOOD SIDE:
-CPVC is relatively inexpensive when compared to copper or PEX.

-CPVC is very user friendly for DIY repair and maintenace because it can be cut with a PVC snap cutter, hack saw, wood saw or a common piece of Nylon Masons twine when used as a wire saw.

-Joints are made using a simple primer and glue procedure that requires no specialized tools or training.

-Pipe and fittings are readily available in all hardware or home supply centers.

-PVC is impervious to the acids occassionally present in the water in some regions that might deteriorate copper pipe or fittings.

-Initial installation costs are usually much lower because the material cost is much less and it is not nearly as labor intensive as running copper.

-Under most plumbing codes CPVC is listed as approved for both supply (line from the municipal main or well source to the structure) and Distribution (Piping within the structure) and may be used both above and below grade without any additional wrapping, coatings or special protection.

ON THE DOWN SIDE:
-When compared to the alternatives (Galvanized iron pipe, Copper pipe & PEX) CPVC is the least durable and would have the shortest expected lifespan under normal circumstances. Having said that, it must be understood that while it may have the shortest life expectancy in the real world it would still provide 25 to 30years or more of service without major problems and in regions that have acidic water that would deteriate copper pipe and fittings CPVC would be a much better choice. (I realize that many will argue PEX is a better choice in areas with acidic water but in truth PEX systems all have copper stub outs and fittings that are subject to the same deteriation as copper pipe.)

-CPVC has a very high linear thermal expansion factor and when installing CPVC provisions must be made to allow for pipe movement under normal use.

-Of all the alternatives CPVC would offer the least resistance to damage resulting from pipes freezing.

-CPVC must be protected from direct sunlight or UV exposure.

-As it ages CPVC will become slightly brittle and must be protected from physical shock or damage.

-When burned, such as in a house fire, CPVC emits a deadly toxic fume.

-For reasons known only to rodents CPVC is highly subject to damage from rats, mice, squirrels and Opossums and may not be a good choice of materials for running under a structure with a crawl space or raised foundation, especially in rural areas.


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RE: what is the downside to cpvc?

There are premium grades of CPVC such as FlowGard Gold. I did my own test of it as soon as it was introduced by hammering it and the conventional CPVC. The FlowGard is much more resistant to impact, but it costs more. I do not use the conventional grade of CPVC.


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RE: what is the downside to cpvc?

Thank you for responding
However,
I wonder why these responses did not come to my email

You are all correct, I mis-stated that they were using CPVC for waste. Indeed, it is plain PVC.

From what I have read about the CPVC, it only might have RVCMs or residual vinyl choloride monomers if it is cheap stuff.

THey are using Flo-Gard and, to his credit, (how unusual) the builder said that I could have copper at no additional expense. I told them to just go ahead and continue with the CPVC.


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RE: what is the downside to cpvc?

I am planing on buying brand new home in NJ.builder had use red color PVC for hot water and gray color for cold water in entire house in hot water baseboard heat and all bathrooms,but i am nervous about it,do you think is safe or i should pass on this house.
any help will greatly appreciated.
thank you


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RE: what is the downside to cpvc?

As far as I know PVC is know supposed to be used for distribution lines in a structure.
Acceptable materials are: copper, galvanized iron pipe, Chlorinated Polyvinyl chloride (CPVC), and in some cases PEX.

Be sure the pipe is actually PVC, there should be markings on it.


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