CPVC or PEX for re-pipe

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Rwbil

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What is the latest thinking on CPVC .vs PEX piping? I read one article that says PEX the best and the next says CPVC best and that insurance companies will not insure homes with PEX (maybe due to the old fitting leaks or thinking it is Poly pipe. I live in Florida with harsh water that puts pinhole leaks in copper. And I read that Chlorine is tough on PEX piping.

Here is what I do know from personal experience, CPVC get brittle over time.

Also if I go with PEX, which way to connect is best the expansion or crimp method.

If anyone has links to independent test that was done on both types of pipes that would be appreciated.

When I go look at new homes they seem to all be putting in CPVC in my area.

But in general which ones causes the least call backs and least to leak or burst over time.

Thanks in advance,
Robert
 

Reach4

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I read one article that says PEX the best and the next says CPVC best and that insurance companies will not insure homes with PEX
Where did you find such an article? It sounds like BS to me.

As a way to connect, I don't know if the expansion is better than the stainless clamps or not, presuming you are thinking that better means less likely to leak. I do know the F1960 expansion fittings have a larger ID. So I expect them to have less pressure loss and turbulence for a given flow.

The expansion fittings cost more.
 

Rwbil

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Where did you find such an article? It sounds like BS to me.

As a way to connect, I don't know if the expansion is better than the stainless clamps or not, presuming you are thinking that better means less likely to leak. I do know the F1960 expansion fittings have a larger ID. So I expect them to have less pressure loss and turbulence for a given flow.

The expansion fittings cost more.

If you are referring to articles about insurance not insuring pex, there are plenty such as:

https://www.nachi.org/forum/f73/no-insurance-cross-linked-polyethylene-plumbing-70946/

From an underwriting document from Tower Hill Insurance (https://oasis.thig.com/chore/help/Getting_Started_...):

"PEX, cross-linked polyethylene, piping is not acceptable. Our extensive claims data indicated that PEX piping is prone to leaking and often results in significant water damage. Please review 4-point inspections and do not submit risks with PEX pipes."


But maybe it was due to the old fitting, I am not sure.

But bottom line do you recommend PEX or CPVC
 

Reach4

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But bottom line do you recommend Pex or CPVC
I am not a plumber.

I am slowly replacing galvanized with AquaPEX with expansion F1960 fittings.

If this insurance thing turns out to be real, that would be very significant.
 

Terry

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I prefer Uponor PEX. It's been used in Europe for decades.
CPVC gets brittle.
Nobody uses polybutelene anymore. Which is what they may have been referring to without knowing it.

sharkbite-poly-pex-coupling.jpg


The gray side is for polybutelene and the other side for copper, PEX and CPVC
 
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Rwbil

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I prefer Uponor PEX. It's been used in Europe for decades.
CPVC gets brittle.
Nobody uses polybutelene anymore. Which is what they may have been referring to without knowing it.

Yes but I read that Europe has very low levels of Chlorine in their water compared to the US and Chlorinecauses problems in Pex piping as shown in this article.

https://failures.wikispaces.com/PEX+Plumbing+Failures

Is there no long term study of the performance of these 2 products over time.


Also, Terry if I went with Pex, I am not crazy about the home run method and the cost of running that much pipe. Maybe a semi trunk and branch method. The ID is also smaller. What size pipe for cold and hot would you recommend and the best way to branch.
 

Jadnashua

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To maintain strength, any plastic pipe would have a smaller ID than the equivalent copper pipe. Polybutylene pipe was a major disaster...it is not the same as pex, which has been around for a long time. Wirsbo/Uphonor adds say more than a billion miles of the stuff are in use worldwide. You do need to protect it from UV, though. There were a couple of other brands that have had issues, but I've not heard of any about Uphonor's stuff (they make their own, rather than it being a rebranded item made for some of the other vendors - maybe the lowest bidder?)

As was mentioned, when you use a crimp connector...the fitting must fit inside of the pipe, further decreasing the ID. ANd, with the memory of PEX, it wants to return to its original dimensions...crimp it, it wants to return to 'normal'. Use expansion fittings...it wants to continue to shrink back to its original size, keeping the fitting clamped all on its own.

It's often easier to just buy one size of pex, use some manifolds, and run home runs. But, you can put it together like a more typical trunk and branch, you just need more sizes to maintain the needed flow rates.
 
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Jadnashua

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Admittedly, you do need some space to make the connections with pex, but you still need some with cpvc as well to spread the cement all around the end of the pipe then put the fittings in place. In the end, pex, because you typically need far fewer fittings and can thread it through sections where you'd have to avoid using cpvc because it's rigid, it tends to be easier. Pex-A is more flexible than the other two types, and can be bent into smaller radii without kinking, so often, to make a turn, you do not need a fitting at all. It ends up being a more professional outcome if you use copper stubouts for connections to things like shutoffs, and often, you can make those connections while it's out in the room, then mount the stubout in place later, so you're not trying to do it in the wall. If you count time, pex should end up being lots faster, and can offset some of the pricing differences.

IF you go with expansion fittings, you would have to be a masochist to do a whole house with a manual expander tool, and the powered ones are expensive. But, you might be able to rent one, or buy a used one, or a new one, then resell it and not lose much.
 
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