Pex in black water pipe

[ytr1903]

I have a black plastic 1 inch pipe that runs underground 85 feet from my basement to the pole barn. The previous owner installed it when he built the house about 15 years ago. A couple of weeks ago, water started seeping through the wall in the basement where the hose came through to the indoor plumbing. (The line that actually comes through the concrete wall of the basement is blue and is evidently "high grade" line versus the black line) I figured that no matter what, I would have to dig a hole at the foundation to repair the leak. So I dug. What I discovered is that the black line runs underground to about 3 feet from the foundation. There a barbed fitting is used to mate to the blue line. The leak is at this fitting. I put an additional hose clamp on the fitting with no change in the leak. At this point, I am guessing that the barbed fitting is bad. My plumber ( who I trust) absolutely hates the black pipe and tells me that if the junction is repaired, it will probably leak again in the future. Anyway, rather than having to dig up the entire run of pipe and replace it, or fix it with a new barb which may fail, I came up with this. What if I run half inch PEX A all the way through the present pipe and just make new PEX type connections at each end? Essentially using the old 1 inch black pipe as a conduit? Is it even possible to run the smaller line that far through the larger line? I can accept the lower volume of water flow because of the smaller diameter pipe.

 

[RobCons]

Wont hurt to try. If the black pipe has been deformed by a rock against it or makes a sharp turn that may be as far as you can go. Will 3/4 inch PEX fit inside the black pipe?

 

[Ultradog MN]

I have a black plastic 1 inch pipe that runs underground 85 feet from my basement to the pole barn. The previous owner installed it when he built the house about 15 years ago. A couple of weeks ago, water started seeping through the wall in the basement where the hose came through to the indoor plumbing. (The line that actually comes through the concrete wall of the basement is blue and is evidently "high grade" line versus the black line) I figured that no matter what, I would have to dig a hole at the foundation to repair the leak. So I dug. What I discovered is that the black line runs underground to about 3 feet from the foundation. There a barbed fitting is used to mate to the blue line. The leak is at this fitting. I put an additional hose clamp on the fitting with no change in the leak. At this point, I am guessing that the barbed fitting is bad. My plumber ( who I trust) absolutely hates the black pipe and tells me that if the junction is repaired, it will probably leak again in the future. Anyway, rather than having to dig up the entire run of pipe and replace it, or fix it with a new barb which may fail, I came up with this. What if I run half inch PEX A all the way through the present pipe and just make new PEX type connections at each end? Essentially using the old 1 inch black pipe as a conduit? Is it even possible to run the smaller line that far through the larger line? I can accept the lower volume of water flow because of the smaller diameter pipe.

I think it is a good idea and you should try it.
Plug the end of the pex before you push it through so it doesn't fill up with crud as you push it through.

 

[chico1]

Please let us know how this works out. I am thinking just friction alone would get hard to overcome let alone bends and constrictions. If there were a way to pull it versus push it, I think it might be more plausible. Maybe run a wire through it with a fish line attached and then attach the line to the pex and with pulling lube try to pull it. Just my thoughts.

 

[TerryfromSWIowa]

Try and blow a sponge through with twine like electricians do to pull wires through conduit. Then you could pull while someone feeds and pushes pex.

 

[Dusty MI]

Use a wet/dry vacuum to suck a nylon string through. If the string is not strong enough, use it to pull a heaver line.

 

[William Eccles - Jardine]

yes using a vac and a cotton or old rag as a mouse on a string suck the line trough >>BUT make certain you tie off the tail end before installing<< other wise the whole line will come through [have seen this happen] Then use a larger pull rope attached to the string for the final pull rope.
lube the final piping with plumbers grease or something similar that won't. affect the plastic piping.
Have fun.

 

[MarkB_MI]

One inch pipe is appropriate for that length of run. 3/4 is probably adequate. I'm pretty sure you'll be unhappy with half inch.

Cut the black polyethylene pipe back a few inches and add a short extension of one inch plastic pipe to reconnect the black and blue pipe ends. Only if that fails would I try anything else.

 

[showcrop]

I can't recall thew details but I recall getting far more resistance to pushing flexible tube into some other tube. Understand that you are going to get a huge loss in flow going from one inch to half inch, just incase you are doing anything that takes flow.

 

[Fred Werring]

One inch pipe is appropriate for that length of run. 3/4 is probably adequate. I'm pretty sure you'll be unhappy with half inch.

Cut the black polyethylene pipe back a few inches and add a short extension of one inch plastic pipe to reconnect the black and blue pipe ends. Only if that fails would I try anything else.

What he said.

I usually warm up the ends of the black plastic pipe with a propane torch....warm up, not burn.. before I tighten down the hose clamps.
Makes it more pliable for the clamp to work. Especially on the pipe that's been in the ground for years.

Good luck

 

[DanielW]

What he said.

I usually warm up the ends of the black plastic pipe with a propane torch....warm up, not burn.. before I tighten down the hose clamps.
Makes it more pliable for the clamp to work. Especially on the pipe that's been in the ground for years.

Good luck

+1 from me as well. In my experience, leaks at barbed fittings of black poly usually occur if the poly wasn't heated prior to putting the barbed fitting in. You want to hold the last 8" or so in uber-hot water (just off the boil) for long enough to make it nice and pliable, then put your barbed fitting in and clamps on while it's still pliable and gooey. Or carefully use a torch as suggested above. I like the boiling water, as it also gives some lubrication so the fittings slide in easily. Brass fittings are strongly preferred too.

I think you'd be really unhappy with 1/2". Loads of repairs have been done to regular black poly, and hundreds of thousands of houses draw their water through black poly just fine.

 

[john in la]

The blue line coming in the house is most likely pex
But the black line outside could be pex but is more likely polyethylene.
To hook polyethylene to pex you need an adapter fitting as pex barbed fittings will not work on polyethylene just like pex A fittings will not work on pex B pipe.
You can either get both barbed to thread fitting for each pipe and screw them together or sharkbite makes a slip on adapter.
Sharkbite fittings are color coded for what type pipe they will work with so you get the correct fitting that has the color code you need on each end.

 

[moresmoke]

+1 from me as well. In my experience, leaks at barbed fittings of black poly usually occur if the poly wasn't heated prior to putting the barbed fitting in. You want to hold the last 8" or so in uber-hot water (just off the boil) for long enough to make it nice and pliable, then put your barbed fitting in and clamps on while it's still pliable and gooey. Or carefully use a torch as suggested above. I like the boiling water, as it also gives some lubrication so the fittings slide in easily. Brass fittings are strongly preferred too.

I think you'd be really unhappy with 1/2". Loads of repairs have been done to regular black poly, and hundreds of thousands of houses draw their water through black poly just fine.

I use a heat gun to warm the pipe, first to insert the barb, then after I have the clamps on I heat it again and retighten. 2 clamps per side on the barb. I use stainless fittings if possible, these days they are generally cheaper and our water doesn't eat them like brass.

 

[1948CaseVAI]

Please let us know how this works out. I am thinking just friction alone would get hard to overcome let alone bends and constrictions. If there were a way to pull it versus push it, I think it might be more plausible. Maybe run a wire through it with a fish line attached and then attach the line to the pex and with pulling lube try to pull it. Just my thoughts.

Use a shop vac to suck a light line through the balck pipe first. Then use that light weight string to pull a heavier nylon line through, then use the nylon line to pull the pex. Hard for me to imagine you can push that pex through all the internal rust and obstruions in the black pipe that you might encounter. Might actually be kind of satisfying to do and kind of fun.

 

[olddavid]

From what I've seen the black plastic pipe is pretty durable and long lasting. I'm not sure why your plumber hates it. Dad used it a lot. As has been suggested a brass barbed fitting and appropriate hardware might be the simplest solution.

 

[Non-farmer]

How deep is it where it comes through your foundation? The mobile home I lived in for a while when I moved here had a shallow well plumbed with black ABS pipe. The stuff was a constant nuisance for the last few feet above and below where it surfaced. I wouldn't hesitate to push half inch PEX through that pipe if I were in your situation. (Now I have a real well and house and the pipe from it comes into my basement about 5 feet under the ground level - they say 40" is needed where I am.)

I've never tried the pulling thing but have seen it mentioned many times. My biggest fear, pushing or pulling, would be that your pipe was spliced at some point and the PEX would catch the end of a barb fitting and stop. If you know it's a single piece of pipe with no splice except for where you've dug out access to it, again, I'd absolutely go for it.

 

[Hemmjo]

A lot of information here. There are any hundreds of thousands, probably millions of black poly installations all over the world that are not leaking. Those that are leaking is because they were executed improperly or improper materials were used. OR, there is mechanical damage from settling fill or sharp rocks damaging the pipe. The plumber only gets called to fix the bad ones, he has no contact with the HUGE number that have not failed.

The keys (many have already been mentioned) are; CLEAN installation. Stainless Steel clamps, even the screws, not just the bands. Two clamps on each barb. Screws OPPOSITE each other. Clamps over the peeks of the barbs, NOT the barbless section close to the center. Metal fittings. Heat before pressing the fittings together. Don't burn, a heat gun is safer unless you are really careful. Keep the pipe warm as you tighten the clamps. SO NOT strip the clamps!!! if you do, put on a new one.

YOU will be unhappy with the flow switching from 1" to 1/2" the flow difference is a factor of 4.

 

[cumminstinkerer]

@Hemmjo you nailed it! installed thousands of feet of it, had had to repair some too, either damage from debris or cheap plastic fittings, I run it for my underground wood boiler lines, zero pressure but 180 degreesish, only issue I've ever had was a clamp that rotted out, cheap crap from a hardware store and not a the good ones from a plumbing supply shop. I was 2 clamps short at install and went the hardware store route, my mistake, dug it up and fixed it right and so far 3 years and no issues.

 

[Wdj]

yes using a vac and a cotton or old rag as a mouse on a string suck the line trough >>BUT make certain you tie off the tail end before installing<< other wise the whole line will come through [have seen this happen] Then use a larger pull rope attached to the string for the final pull rope.
lube the final piping with plumbers grease or something similar that won't. affect the plastic piping.
Have fun.

@Hemmjo you nailed it! installed thousands of feet of it, had had to repair some too, either damage from debris or cheap plastic fittings, I run it for my underground wood boiler lines, zero pressure but 180 degreesish, only issue I've ever had was a clamp that rotted out, cheap crap from a hardware store and not a the good ones from a plumbing supply shop. I was 2 clamps short at install and went the hardware store route, my mistake, dug it up and fixed it right and so far 3 years and no issues.

You're running 180 degrees through black plastic? If that's working long term I wanna know more. Or maybe I misunderstood.

 

[cjunrau]

I have a black plastic 1 inch pipe that runs underground 85 feet from my basement to the pole barn. The previous owner installed it when he built the house about 15 years ago. A couple of weeks ago, water started seeping through the wall in the basement where the hose came through to the indoor plumbing. (The line that actually comes through the concrete wall of the basement is blue and is evidently "high grade" line versus the black line) I figured that no matter what, I would have to dig a hole at the foundation to repair the leak. So I dug. What I discovered is that the black line runs underground to about 3 feet from the foundation. There a barbed fitting is used to mate to the blue line. The leak is at this fitting. I put an additional hose clamp on the fitting with no change in the leak. At this point, I am guessing that the barbed fitting is bad. My plumber ( who I trust) absolutely hates the black pipe and tells me that if the junction is repaired, it will probably leak again in the future. Anyway, rather than having to dig up the entire run of pipe and replace it, or fix it with a new barb which may fail, I came up with this. What if I run half inch PEX A all the way through the present pipe and just make new PEX type connections at each end? Essentially using the old 1 inch black pipe as a conduit? Is it even possible to run the smaller line that far through the larger line? I can accept the lower volume of water flow because of the smaller diameter pipe.

I would do it. as far as not enough volume. Just ad a tank in the other building. that way the volume is there already.