Our main water line from our well broke recently. It is presently 2-inch copper, somewhere between ten and forty years old. The plumber who patched it said it is paper thin, probably because our well water is fairly acidic. We’re getting bids to have it replaced. However, one guy says we should replace it with 1″ 200 PSI polyethylene, since copper would corrode, and the other guy say that we should replace it with 2″ copper again, because anything else splits or cracks. When we asked him if the acidity of the water wouldn’t damage copper pipe, he said the risk of a non-metal line splitting was greater than the risk that the copper would corrode. Who should we believe? Are there guidelines for water line installation? Code?
Thanks,
Susan
Replies
If corrosion is a problem, go poly. I use a pipe with a SDR-11 rating (wall thickness of 1/8"). Bursting has not been a problem up to at least 140 psi. The stuff is sturdy. Write back if you cant find it.
Ted
All the natural gas lines i see now are a PEX or its relative. They bury those under the streets to feed the houses.
Copper pipe is soft, and if its not laid right it will burst or fracture just as easy as the plastics. With copper there are joints that cant fail, Plastics on the other hand have usually two joints, one to connect each end. Little chance for the good ole human error.
If you choose the plasitcs route, ask that the plumber tape some thick copper wire so that later you can use a good metal detector to locate the pex in case of unexpected need or if you excavate near there in the future
Bill_1010 is right about the trace wire. Especially if the pipe will be a long one that could go any of many ways. We add them to many trench runs. They can save quite a bit of head scratching and extra work.
If you have 2" copper and wish to replace it with 1" poly why not run it through the copper pipe and eliminate the digging. Don
Joints, Elbows and the inevitable, in theory yes, in practice no.
(refering to the pe tubing throught the old line.)
Susan,
I have a 1" polypropylene line that is 30 plus years old. Polyethylene, especially the crosslinked variety, is very popular for infloor tubes and indoor plubing. I don't know how suitable it is for direct burial. Had to excavate the area and took a close look at the line to see if replacement while it was exposed would be worth while. Looked as good as new. No cracking or degradation externally. The ground is failrly acidic but the water is a little on the alkyline side, very hard.
As far as the copper goes, it depends on what type. Type M is the thinnest, cheapest pipe you can get (I would not recomment using this for anything but garden art), type L is thicker walled and is well suited for indoor use, type K is thicker walled and the best suited for direct burial.
Depending on where you live the state plumbing code or the International plubing code will apply, but it probably will not restrict the material, much. The local buiding and zoning folks should be able to identify the applicable code.
My choice would be use the polypropylene. Phillips 66 makes a product called Driscopipe. As far as I know, the best stuff there is for buried (uninsulated) pipe.
Your copper guy is ignorant. He does not know the facts. Do you want him working on YOUR waterline?
I would tell him that I found out he is so far behind the times I would not hire him at any price. What a moron. He is either stupid or else flat out LYING to you about the plastic splitting, etc.
I know his type. There are many plumbers like that and their mental abilities are some higher than a rock. I think...
I would not consider any product (galvanized, copper, PVC, etc.) for the water line you described except black poly that (1) is rated at 200 psi and (2) carries the NSF "potable water" stamp.
You might keep a couple of points in mind, however: First, because of the wall thickness, it'll take two people and a mule to unwind a 100' roll. If it's cold, substitute "backhoe" for "mule". If you can wait to do this on a bright sunny day or have a way of running hot water through the pipe first, it'll be much more flexible. And it's a lot easier to get into the trench if this can be done a day or so ahead to allow the pipe to lose some of its "springiness".
Second--again because of the wall thickness--it is possible to use compression fittings with 200 psi pipe as an alternative to the barb-fitting-and-circle-clamp route. If you do use the barbed fittings, stick the end of the pipe into almost-boiling water for 30 seconds or so to soften it enough to push the barb in; and use TWO stainless steel circle clamps for each fitting.
And finally: Poly pipe WILL expand and contract a tiny bit--even though it's buried in the ground--due to changes in temperature. Therefore, it's important for the long-term life of the pipe that it be "bedded" in small gravel, rockless dirt, or sand before the trench is backfilled. Otherwise, if it's resting on a sharp rock, the tiny back-and-forth movement can (in a couple of years) puncture a hole in the line. Which you won't notice until you discover this new spring on your property. Which can be located 50' away from where the hole is in the line....
Why would you exclude superior piping in this situation?
Tough question to answer, the way it's phrased, so let me begin by emphasizing that's there's a WORLD of difference between the thin-walled polyethylene "tubing" that's rated for 100 psi (and may even have "cold water use only") stamped on it and what I was recommending.
It's my honest opinion that black poly pipe that's rated for 200 psi and has the National Sanitation Foundation stamp indicating that it's designed for potable water IS the superior product for the installation Susan described for the following reasons: 20' sticks of galvanized, PVC, or copper will have four more joints for every 100' of run than the poly will, so there's that many more opportunities for leaks; poly does not require the degree of skill and experience that properly gluing PVC, soldering copper, or screwing together galvanized pipe does; it is chemically inert and is unaffected by electrolysis, or acidic or alkaline soil; and--after factoring in the labor cost--it's the cheapest of the alternatives mentioned.
Would I use it inside the house? No, I'd scrimp on something else so I could afford copper. But as a retired facilities manager who's been in charge of the construction or maintenance of 15 buildings, I can tell you that the only time we ever had a problem with a water service line it was corroded copper.
Edited 8/13/2002 8:18:31 PM ET by Mac
Yeah, I understand now. There are other good products similar to what you describe available. I rate them all better than copper, galvinized, or PVC for this application.
To be more clear I meant Polyethelene. Definetly burry a wire. #12 copper should be fine. Use insulated wirejust to be sure it does'nt corrode. If you are'nt in a freezing climate try to make your connections above ground, say on a post with a hose bib or in a box in the ground. The odds of a leak in the rest of the pipe are slim and if you do have a leak you can rule out the connections.
Thanks for all your replies. They are very helpful. We're going to go with the poly pipe and the contractor with fifty years of experience with local well and water system installations. We're new homeowners of a 50-year-old ranch house that's been upgraded a couple of times in the past -- there are new surprises every day. It's nice to have this source of experienced advice. Thanks again --
Susan
I didn't see it listed as a benefit but around here from what I have seen, depending on soil conditions, the material used and the particular installation, lots of poly pipe is installed by plowing it in with a vibratory plow. This can save money on trenching and limit damage to the lawn and landscaping. The idea of using the original copper run as a sleeve seems good also. Best of luck on your project.
Trenching and backfill is as important as the material. I only saw one brief mention of it above. The trench should be overexcavated by min 4-inches and filled with pea gravel or sand. After the pipe is layed, an additional 4 inches of bedding should cover the pipe. The trench should be bacfilled and COMPACTED, especially if it is shallow or in a traffic area (ie riding mower).
Craig S. Blett, PE
I haven't worked with a well head pipe, however I have worked with a golf course irrigation system. The sand as a backfill is a god send. If you ever have trouble it is very easy to dig up, and being easy you are less likely to jam the shovel into the pipe while you're excavating to fix and cause more damage. The pipes we used for the golf course were from 1 1/2" to 4" PVC with a burst pressure of 300 psi.(if memmory serves well). The service pressure was 160 PSI.