PEX Problem

Is the manufacturers name and product "LOT" number stamped anywhere along the side of the tube?

If so, try contacting the manufacturer.

Also try to Google "PEX Tube Manufacturers"

I only installed PEX once in a home I used to own but 10 to 12 years sounds to be a rather short life span to me.

On the other hand, isn't PEX designed for direct burial only? Maybe the heat did it in.

I'm no expert on the subject. Just a few thoughts!

I excerpted this from Mark's post.

"PEX is cross-linked polyethylene and it is not ordinary polyethylene pipe.

PE stands for polyethylene and X for cross-linking.

The material's chemical abbreviation is PE-X.

There is PEX specifically made for potable (drinking) water.

There is PEX made for under floor piping and there is PEX specifically made for radiation type heating.

We realize that not all PEX pipe is the same and that makes it very difficult for us to "know" what is "best."

And that's coming from the plumbing experts.

I'm trying to locate the plumber that installed it, I know he is still in business, I hope he has better records than I do. At this time I'm recovering from a broken leg and can not climb into my attic to look for lot # or manufacturer's name. PEX does not have to be buried, but it does have to be protected from sunlight. Thanks for the info.

I have to ask. Are you sure it's not poly-butylene tubing?

I haven't installed any PEX in my house yet, but I've been told that it is almost indestructible, hot or cold. Best thing since sliced bread.

Here is some interesting reading on PEX.

"I have to ask. Are you sure it's not poly-butylene tubing?

I haven't installed any PEX in my house yet, but I've been told that it is almost indestructible, hot or cold. Best thing since sliced bread.

Here is some interesting reading on PEX."

I'm not sure, but I paid for PEX. Now I wish I had re-plumbed with Stainless Steel, because the original Copper Tubing corroded from the inside.

Copper tubing corrodes from the inside when other metals are also present in the water, it forms a sediment at the lowest point of they system and a gas (Hydrogen I believe) that can be set fire to and burns with a blue flame......

You did not mention if this was circulating water or not.....if not circulating, its harder to fix....plastic fittings may help further, though I have not personally tested that either.....

The PEX, and generally plastic tubing for household water, underfloor heating, and gas underwent a couple of technological changes in that timespan. And if I am not mistaken, the crimping got changed once too. The tubing got at least 2 crosslinking material upgrade, and 1 or two webbing upgrade to better deal with cracking, high temperature water, and contaminants in the gas supply, in addition to life expectancy extension in floor heat.

Sorry, the good news is that NOW it seems mature. Talking with a master plumber you might get confirmation by his experience: any warranty question is not resting on his shoulders, but on the maker's.

I hope to determine the manufacturer, so that I can get them to pay for the replacement. The plumber did nothing wrong, the product simply failed. But, I do get tired of hearing 'We've never seen this happen before'.

You could go back with Type K copper. It has much more wall thickness than the usual type M. I'd wonder about the chemistry of water that ate up your previous copper!

City of Tulsa Oklahoma water from surface water sources. Birds fly over, fish swim in, duck and geese float on, and occasional lake turn over given the distinct taste of algae.

Sounds like you need to do what my buddy Ken did in Owasso, OK. Whole house filtration. $1,500.00 dollar investment and $100 in Cartridges quarterly. He had a problem with the copper disintegrating from the inside out and thought about his guts after that. He re-piped 10 years ago and recently cut a line open to see if the filtration system has been doing its job. Shiny clean copper is what he found.

As far as PEX I hate to climb on the band waggon but I have never seen PEX deteriorate even in extreme heat / Cold climate changes like an attic in OK.

But hey, you could be the very first..........somebody has to be #1.

I'll give you a scenario that happened to me. It sounds crazy, but it's true. My HVAC people installed PEX to provide a drain for my air conditioning condensate pan. It worked fine for a number of years. Then one summer the ceiling below developed a water stain. Analysis revealed that the previous hot summer the attic got very hot and the PEX pipe formed a permanent sag that became a water trap. The following winter the water in the trap froze and split the tubing. The next summer the condensate leaked from splits and ruined my ceiling.

Wow!!!

At least you know the whole story!!

One thing could of happened is when an installer pulls pex up to a second floor, sometimes it is very uncomfortable to watch every little corner where the pipe is being pulled through.

Maybe it was sliding on a nail or edge of metal strapping. Not cut totally through at the time of installation and over time with heat/expansion/sag/movement,it could weaken and begin to leak

PS Didn't Europe have pex way before it was allowed in the US?

If the temperature was 100°, the temperature in the attic could be 20°higher & this combined with high pressure could lead to the crack, if you've ever left a water hose laying on a paved area in the heat of the day under pressure they can blow, I've had it happen, also the temperature on the slab is usually too hot to walk on in bare feet, So my guess is heat & pressure combined.

For the best ,currently available, check out: http://www.aquathermpipe.com/

http://en.wikipedia.org/wiki/Cross-linked_polyethylene Read this, and all will be revealed! Looks like your plumber got hold of a bad batch, and you would be well advised to replace any thats not well supported, or exposed to extreme temperature. Hope the leg mends soon, and good luck.

I think you found the answer to the problem , at least this looks like the most probable cause the way everything is described. I assume the manufacture would like to look into this particular pipe. If it is found to be a defective pipe, how far the company will go to replace the installed pipe and pay for the labour and any of the damages caused by the cracked pipe remains to be seen.

These answers puzzle me. Pex is in almost universal use throughout the plumbing world. Very few residential projects are using other materials, (copper, PVC, etc.) and even some commercial projects use PEX. It is common for radiant heat, potable hot and cold domestic supply.

Your description is a classic example of frozen pex, which probably survived multiple cycles before failing. It is true that the ultimate strength is reduced at high temps, but it is all rated to 180F. Any other material would have failed long before, if exposed to freezing. This attribute (freeze thaw survival rate) alone has made PEX more reliable for most installations.

The post with the sag would only apply if you were using the supply line periodically, as they are always full in a typical DHW or DCW home distribution systems..

Anyway, cut it out, put it under the attic insulation (at least 12" cellulose), inside good pipe insulation. If you find out it is not pex, replace it with pex.

The cracks, both the internal and the one through crack are all in a single line along one side only and has not been through repeated freeze cycles.

W/o freeze thaw cycles I would have to say (from this distance) that the plumber got a bad batch. As stated previously, PEX is rated to 180°F at delivered water pressure, so unless your attic space is knocking on 200°F it is not likely that the heat should have had anything to do with it (if it was a bad batch the heat may have exacerbated the material flaws). It may also be possible that there are some dissolved chemicals that are attacking the cell structure of that batch of PEX. That was the problem with polybutelene water piping - the chlorine in domestic systems attacked the material from the inside until ultimate failure.

If I were in your shoes I would replumb with PEX (I have plumbed quite a bit with PEX and Cu) but again as stated previously, get all of the info from the pipe and keep whatever you have replaced as it will be the key to the problem. Maybe while your leg is mending you can send a minion - er - friend up and have them get the pipe info. Good luck and quick healing!

I suspect there will be more causes for this problem, we can start with the types of cross-links .Generally using three types of cross-links namely Peroxide links PEXa , silane cross links- PEXb and cross-linking using electric beam radiation PEXc.. PEXa having 80 to 90% cross-links, PEXb is 65 to 70% and 65 to 70 % for PEXc. In which PEXa will be fully cross-linkedwith in the extrusion screw barrel. But for PEXb will be up to 40% cross-links during the processing procedure, then it need to keep insteam vessels (normally called sauna vessels) or need to submerge in hot water for some days to achieve 65 to 70 % cross-links

For the ease of processing, manufactures using PEXb (because scorching of the raw material is less and ease of cleaning the screw barrel) But most of the manufacturers will not spare the time for steam maturation for achieving the required degree of cross links and says as PEX is using mainly for hot water application, so when hot water passes through it ,it will cross-links to 65 to 70%, but if the same pipe is used in cold water!!! the crosslinks remains 40% and this will adversely affect the mechanical properties of pipe resulting a crack.(you didn't mentioned the operating pressure) according to DIN standards PEX pipe will be stable up to 10 bar @ 95C.

Another cause of the crack may be with PEXa though it have a high degree of cross-links,cold expansion will be high ,and you said that it is using for 10 - 12 years ,as I told about cold expansion and the pipe is using in the attic for cooling and heating the room ,the cyclic expansion and stagnation or shrinkage will results a lengthwise crack .You already told the pex tube is inside a foam insulating sleeve ,so there is no chance to have a UV exposure (PEX is having very low UV stability) if there is a small exposure for a long times leads to the breakage of the cross links and the crack will propagate .and also if we using chlorinated water in the tube will also increase the intensity of the failure.

I believe it is the house potable hot water line 160F (71C) at 80 to 100 PSI (5.5 to 8 bar).

Can you take pictures of the cracks, preferably nice, radial cuts of the pipe and microscopic pictures.

Use it all the time since 1989 and hate to say it but I've never heard of this happening before.

Usually not necessary to insulate it as it is self-insulating and manufactures say not too.

The insulation may have caused excessive heat buildup above manufactures recommended specs if it was the hot water line.

The only time I've seen it split is when it got ran over and crushed by the plumbers truck in the driveway.

http://www.ppfahome.org/pex/faqpex.html

It looks like it's quite possible that your installer let the pipe sit in the sun for too long before installing it. From the sounds of the link, just letting it sit in the back of a pickup truck for a day could compomise it's integrity.

I hope that is not the case, but I do not think it had been in use for long in Tulsa at the time of my install. The plumber may not have known that a relative short sunlight exposure could compromise the PEX. I having the plumber that repaired the leak come back and examine the rest of the PEX and provide an estimate to replace it.

Hopefully, it is a manufacturing defect, or at least the problem is confined to a short section, not likely haha.

I read somewhere about trouble with PEX made by a particular manufacturer, apparently the stuff was so bad there is a class action law suit in both Canada and the US for people trying to recover damages caused by the faulty material.

Might be worth a check to see what type of PEX you have. Google found this link.

Class Action PEX Lawsuit