Our water line from the township's shutoff to the house* is polyethylene
and has sprung a leak. The quote to replace it with PEX is $1475; copper
would be about $500 more.
The plumber said PEX should be good for 20 years or more; the guy from
the township who came to shut off the water said they still use copper.
Any informed opinions here about which we should choose?
*Actually about 6ft from the house: that much of the poly pipe was
replaced by copper about six years ago when we had water trickling down
the inside of our basement wall.
PEX should last longer than that.
The reason the town is using copper is because they have deep pockets
(yours) and "we always did i that way" mentality.
I'd go with PEX and use the $500 difference for something else.
I expect the reason why the town is still using copper is because their
workers are familiar with copper and know what to do with it.
Every time you introduce something new somewhere, someone somehow is
going to do it wrong or screw it up some way. As long as the town
sticks with what everyone knows, then they have a minimum number of
A $500 incremental cost to use copper may not be unreasonable. For
underground pipe installations, my understanding is that the plumbing
code requires that Type K copper pipe be used, and that's the pipe with
the thickest wall, so it's the most expensive. Combine that with a 100
foot long driveway and I could see the incremental price getting way up
Still, it wouldn't do any harm to get another estimate or two.
The pipe is 5ft deep, so I don't see repairing it myself. The township
guy who came to shut off the water said that some people do just patch
but often end up having to redo it every couple of years.
On Monday, April 7, 2014 4:12:45 PM UTC-4, CRNG wrote:
For what it's worth, here in the NJ suburbs they've been using
the black poly for decades as the preferred method. It's lasted
30 years here in my house, IDK of any neighbors with any problems
and it;s all that I see going into new construction. I wonder if
this was a bad lot, some cheap crap, etc. I'd have no issues using
On Monday, April 7, 2014 8:33:44 PM UTC-4, Ed Pawlowski wrote:
And your reference that poly won't last a similar amount of time is?
It's been on my house, all my neighbors houses for 30 years now and
I haven't heard of a single failure. If it doesn't perform well,
rather odd it's still approved and used. And I'd also point out that
you're comparing something that is relatively new, ie PEX, to something
that has been widely used for 30+ years. There have been other new
plumbing materials that were thought to be great ideas, where after
a couple decades of use, they turned out to have major problems.
I'm not saying that PEX wouldn't be perfectly fine, just that until
it's been in that kind of application for 30 years, I don't think
you have the data that shows it's any better.
The township guy who cam to shut off the water said they do a couple of
these a week. Our neighbor one side already had the same problem a few
Perhaps there was a problem with the particular grade of polyethylene
pipe that was being used at the time.
Anyway, we were not offered the option of using polyethylene: PEX or
copper were the choices, and we're going with PEX.
On Tuesday, April 8, 2014 11:03:20 AM UTC-4, Ed Pawlowski wrote:
I didn't say to patch it. I said I don't see anything wrong with using black
poly in that application. Just because he's having problems doesn't mean
much. If he had problems with PEX, would that make all PEC bad? God knows
who made the poly. It could have been a bad lot, bad manufacturer, etc.
PEX tubing sure hasn't been used around here for anywhere near that long.
It's only showed up in about the last decade and for water service
to the house, I see black poly in new construction. The new construction
I've seen isn't using PEX for anything, either. Also, I believe PEX
wasn't even allowed by code in some places, eg CA until a few years ago.
I'm not saying anything is wrong with PEX. If I was the OP, I'd probably use
it too. I'm only saying that I haven't seen any real data that says
poly is no good for this application, that PEX is going to last longer,
etc. Some failures of any piping in one area, don't really prove anything,
unless the actual cause is determined.
I had to replace my copper line a couple of years ago. The pipe had been in
the ground for at least 40 years but from its looks it could have been from
an Egyptian archeological dig. The original 3/4" pipe seems to have been an
early type K but the walls were down to paper thickness in spots. This
seems to have been caused by chemical erosion inside and outside as well as
physical damage to the outside from minute soil movements and abrasion. New
type K coated for direct burial would have probably held up better than the
old pipe but my plumber said that PEX was the way to go and that nobody
locally was using copper any more, there being no code requirements either way.
Why not use galvanized steel pipe from the street into the house?
Isin't Pex made with aluminum tubing with some sort of blue plastic
liner on the inside and outside?
I hooked up a small electric water heater using pex about 8 years ago,
hooked it into what was a hot/cold faucet in a janitor's closet. Used
pex to supply hot/cold water to a nearby kitchen sink. So I can see all
the pex lines, and the pex is holding up without leaking.
No don't use galvanized steel. It rusts, and that's why people with
galvanized steel water supply piping spend big bucks to replace it with
either copper or PEX.
The only time galvanized steel will outlast grandma is when you use it
for the piping of a hot water heating system. But, in that situation,
all the oxygen dissolved in the water is either driven out of solution
by the heat or reacts to form rust in the hottest spot, which is the
boiler. All the hardness ions form scale in the hottest parts of the
heating system, which is the boiler itself. So, the vast majority of
the time, the water flowing in those galvanized steel pipes will be both
oxygen depleted and ionically dead. The iron doesn't rust because
there's no oxygen to form Fe3O4, and the pipes don't cake up with scale
on the inside because all the scale forms in the boiler. So, in a hot
water heating system is about the only time you wanna use steel water
piping. I once had to replace one of my steel water pipes going to a
radiator, and after about 40 years in service, the thing looked like a
brand new steel pipe on the inside. No corrosion or scale at all.
PEX actually stands for PolyEthylene (Crosslinked). So, polyethylene is
a very strong hydrocarbon chain, and crosslinked polyethylene has
crosslinks between the hydrocarbon chains to increase the strength and
rigidity of the plastic. There's no aluminum involved. The PEX tubing
gets crimped onto special PEX fittings with a special crimping tool, so
plumbing repairs can be done even when there's water leaking in the
pipe, which is a great blessing.
=========PEX-AL-PEX pipes, or AluPEX, or PEX/Aluminum/PEX, are made of a layer of
aluminum sandwiched between two layers of PEX. The metal layer serves as
an oxygen barrier, stopping the oxygen diffusion through the polymer
matrix, so it cannot dissolve into the water in the tube and corrode the
metal components of the system. The aluminium layer is thin,
typically 1 or 2 mm, and provides some rigidity to the tube such that
when bent it retains the shape formed (normal PEX tube will spring back
to straight). The aluminium layer also provides additional structural
rigidity such that the tube will be suitable for higher safe operating
temperatures and pressures.
That's the pex I worked with 8 years ago for a small plumbing project.
So in my mind, pex is always an alumimum pipe sandwiched between two
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