Why is my plumber suggesting that I replace the poly water supply line to my house?

Question

All the houses in my subdivision were built in 1985, and they all have poly main water lines to the house. My line is spraying water right at the fitting that connects to my water meter.

The plumber tells me the fitting for this type of poly pipe is no longer made nor available, and said everyone with this poly usually just replaces the whole line, (for $4500). He recommends Wirsbo Propex. In other words, he says that he can't just cut off the leaking section of line because he has no fittings to reconnect it to the meter. (I'm not sure I can believe all this, as naturally he'd rather do the $4500 repair.)

There are plenty of YouTube poly videos showing how quick and easy DIY it is to add connectors to this line. Some are simply metal inserts that are barbed on one side (inserted into the poly after heating it) and threaded screws on the other, then you screw an adaptor on to connect to any type of line you want, copper, PVC, pex, etc. Thing is, I can't find any of these fittings online, but maybe I just haven't searched enough. I could repair this myself if I could find these fittings.

It also just occurred to me that this poly line is really large, diameter wise, much larger than the 3/4" pipes used in the house. Instead of digging up the whole yard, I'm wondering if I can't snake a smaller diameter (1/2") PEX line through the poly, from the meter to the house. It's a fairly straight shot from what I can tell. It has the added bonus of acting like an insulator/protective covering.

Any thoughts or comments?

Answer 1

I have a feeling that we're actually talking about polybutylene, which is obsolete and could account for the confusion. I think most of us assumed you're talking about polyethylene, which is commonly used today.

Your home was built during the window in which polybutylene pipe was used for runs from the street to the meter. It was discontinued due to lack of durability:

While scientific evidence is scarce, it is believed that oxidants in the public water supplies, such as chlorine, react with the polybutylene piping and acetal fittings causing them to scale and flake and become brittle.

This would also explain your plumber's suggestion, which seems reasonable in that case. Due to slightly different wall thickness, commonly available fittings cannot be used. Any plumber who cares to stand behind his/her work may also be reluctant to work on PB, since it's more likely to result in a callback. You might point out that SharkBite offers transition fittings, which can be identified by their gray plastic sleeves. So a solution may be at hand.

"Black poly" isn't really a thing, officially. It's a layperson's term for an unknown plastic or a tradesperson's nickname for polyethylene that happens to be black. Color is irrelevant with these materials, though.

Answer 2

Sounds like your plumber is might be a crook/scam artist.

Black polyethlyene pipe (also known as well pipe) for cold water distribution is still very standard and available as are the fittings for it. The folks who make blue polyethlyene well pipe make some dubious claims that it's "better" but I can't say I find them at all convincing, and the price differential is large. The black stuff is listed by NSF as suitable for potable water. So's the blue stuff. They use the same fittings anyway. The rest is marketing BS.

Digging up the whole line to replace it is ludicrous - black polyethlyene is not like the gray butyl they used inside houses for a while that "just fails" and you really should replace the whole set - I've personally worked on black polyethlyene well pipe from 1964 or so, and aside from the misery of getting connectors out of it without just sawing the pipe off (didn't want to lose the length that would take) it was just fine 50 odd years on.

It would be advisable to evaluate why the pipe at your water meter broke (is it exposed to damage? Frost movement or freezing?) but there is no reason at all to replace black polyethlyene with pex, wholesale, particularly if it means digging up the line.

Picture is from Aqua Science, one of many online vendors that have them. A hardware store near you probably also has the correct fittings. I have purchased stuff from Aqua Science but have no other relationship with them.