Black Poly Pipe: How long does it last?

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Ted M

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My house is about 35 years old; maybe 1979. I bought it in 1987.

The black poly pipe runs about 30 feet underground from the well and then another 25 feet under the concrete footing and concrete basement floor. It sticks up out of the concrete about one foot near the captive tank.

The ID is 1 inch, and the OD is about 1.37 inches. I do not know the pressure rating. No well info.

Today I received a letter from some uninvited insurance company wanting to insure the piping, for $65 a year.
They claim the well pipe was installed in 1977. No idea how they could tell. Could be correct though.

So, how long should this underground black pipe (about five feet underground, then under finished basement) be OK?

Thank you.

Ted
 
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Terry

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I replaced my 1978 black poly pipe five years ago. I had more like 50 feet.
Most of the time, it's becauses something like a tree root had grown around it, or rocks have rubbed against it.
Five feet? I don't think I would worry about that.
 

Valveman

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I agree with Terry. I know where there is lots of poly pipe still working since the 70's. As long as it doesn't rub on a rock or have tree roots growing around it, it will be fine.
 

Hader

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"or have tree roots growing around it"

Is there a solution or a better way if there's a lot of trees around? I have to run 200'+ next to a tree line. There's isn't 1 SqFt without some kind of roots in this property.
 

Valveman

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Tree roots will push and pull on any kind of pipe. But poly is more flexible and is as good as you can get with tree roots. Roots will also grow into the connections under the barb fittings and around and into threads. Been replacing all of mine with the same HDPE type pipe but is butt fused or welded together so there is no place for the roots to get in.
 

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Our situation has Critical Area Ordinance restrictions due to steep terrain, and frequent problems with roots, falling trees, and the soil shifting. One spot where the pipe cement puddled, cracked and had a 6 GPM leak. 1400'? of 1" thin-wall PVC, and no locator wire.
Whoever put it in back in the '70s used SDR26 (0.070" wall) 1" PVC, probably because of price and better flow (larger ID). Quite fragile.
We're looking at horizontal boring and 4" well casing, running separate plastic pipes inside of it. 500'.
 

Reach4

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Our situation has Critical Area Ordinance restrictions due to steep terrain, and frequent problems with roots, falling trees, and the soil shifting. One spot where the pipe cement puddled, cracked and had a 6 GPM leak. 1400'? of 1" thin-wall PVC, and no locator wire.
Whoever put it in back in the '70s used SDR26 (0.070" wall) 1" PVC, probably because of price and better flow (larger ID). Quite fragile.
We're looking at horizontal boring and 4" well casing, running separate plastic pipes inside of it. 500'.
4" well casing? As a conduit to contain poly??? Sounds like overkill. If you are referring to your well, I would have some comments on that.

Thermal effects may have contributed to the failure.

With poly, you still have that, but usually deal with it by not pulling the pipe tight, and instead snaking it in the trench.
 

Valveman

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I think even if you put poly in 4" conduit it will come apart if you run it straight. Got to have some curves. I have been dealing with about 7K feet of 1.5" heavy wall poly (for the rocks) in similar conditions. Don't have terrain problems but all the rest. The only problems I have had was where the line ran too straight and where I used threaded fittings or compression couplings to make connections. The roots grow under the o-rings of the compression couplings and around the threads in a threaded fittings until they cause a leak. It doesn't help that poly will contract or expand 1" for every 100' with every 10 degrees of temperature change. My discharge line if from a heat pump and the temp changes 60 degrees from AC to heat times of the year. This makes my pipe line get 11' longer or shorter depending on the time of year. Yours will probably change by about 3' or so with a 30 degree difference in soil temp from wither to summer. In the straight parts of the line it won't have any give. So, just snake it down the hill as best as you can. Butt fuse welding at the connections is also a must.
 

Technophile

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4" well casing? As a conduit to contain poly??? Sounds like overkill. If you are referring to your well, I would have some comments on that.

Thermal effects may have contributed to the failure.

With poly, you still have that, but usually deal with it by not pulling the pipe tight, and instead snaking it in the trench.
I appreciate the tip about expansion. It's a cold water line 2..6' (or more) down so I'm not expecting too much change in temperature, but some will occur. The outer pipe would expand some too.

Shared project; running 3..4 lines in it, depending on what a neighbor decides. Probably going to order continuous lengths of pipe to avoid lumps, weak spots when pulling, and having sharp hose clamp tails rubbing on the adjacent pipes.

We are not legally allowed to trench because it's through steep terrain (up to 45° slopes in some spots) and it rains; erosion. To give you an idea, the water main is at about 84 PSI; we get 25 PSI (static with no flow) due to elevation gain. We don't seem to have any other options unless we want to haul water or do rainwater harvesting.

Trees fall and take whatever their root system runs through with them; stub branches on the about-to-be-down side stab into the ground. A neighbor recently had a pipe joint pulled apart just from roots growing: there was a couple inch diameter root running through the center of the pipe bundle; see pic.

Wondering what kind of force we'll need to drag the pipe bundle? Planning to use lots of wire pulling lube and get mule tape. The well driller may or may not pull the pipes in for us.
 

c094728

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I'm reading lots of conflicting information on what pipe will last the longest. I need to replace about 25ft of pipe from my well to my house that was galvanized steel about 50 years old and buried 4-5 ft deep. A joint sprung a leak and the inside is full of mineral deposits and decay reducing the inside diameter to about 3/4". I'm thinking of using 1" 200psi black poly but someone said go with 1" pex while others say PVC is the way to go. Any thoughts? Will poly collect mineral deposits the same as the steel did? There are tree roots in the area
 

Reach4

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My well has 3/4 poly inside of the original 1-1/4 steel. It is a straight shot.

Even if you are planning a new trench, you could use that method to enter the basement. Whichever you use, entering the basement is a consideration.

SIDR poly is bigger ID than the same nominal size of PEX.
 
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