Locate PVC pipe

Submitted by iamintheforest t3_123wj25 in DIY

Because i'm brilliant I put a 4" PVC pipe under my driveway when I was doing landscaping - it's about 60 feet. I now need to use that chase and I can find one end.

Because I'm NOT actually brilliant, I cannot recall where the other end is exactly and exploratory shovel work leads to tears. Is there a good detector that lets me run something through the pipe and then locate it from above ground? Basically...a metal detector, but where I can detect a specific signal (there is other metal in the ground in the area).

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minesskiier t1_jdwmgtj wrote

You could rent a pipe/drain camera that has a locator built into the head. Or pay a plumping company to do the same.

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Diligent_Nature t1_jdwmr92 wrote

If it isn't too deep you could run a snake through it and use a metal detector.

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iamintheforest OP t1_jdwqlit wrote

i've done that. Just runs me into the other metal that is the vicinity and then i'm just back to exploratory shoveling!

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Strange-Grand t1_jdws973 wrote

Put something big on the end of the snake. A gasline fitting would work. Zero the metal detector in the place you will be holding it. You need someone to move the snake in and out about a meter while you hold the metal detector still. When you get a hit, mark it and move in a grid. Rezero, and repeat until you determine where the center of the strongest signal is. If it isnt too deep, you could use a powerful fishing magnet as well.

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NGC6753 t1_jdwny7s wrote

Do you mean something like this?

https://www.amazon.com/Blockage-Detector-Underground-Diagnostic-Tool-Instrument/dp/B0BFH7ZTW9/ref=mp_s_a_1_4?crid=1BWCN8N3Z4AP9&keywords=pvc+pipe+locator+underground&qid=1679943889&sprefix=pvc+pipe+lovator%2Caps%2C328&sr=8-4

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iamintheforest OP t1_jdwqtzg wrote

I do! I hope this can work through dirt instead of just walls/studs, etc. Giving it a try - thanks for the suggestion.

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NGC6753 t1_jdwt8k9 wrote

I have used similar, for a similar problems.

With the first the pipe was about 30cm/ 1 foot, down under concrete paving slabs and sand/soil and it worked just fine. With the second the pipe turned out to be a lot deeper than I had been told and the sensor could not pick it up. For that I just pushed the probe as far into the pipe as it would go, put a piece of tape on the probe cable before I pulled it out of the pipe to indicate the length used then laid it out on the surface so I could mark the approximate position of the other end. I was about 20cm off so no big problem.

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PublicRedditor t1_jdwrkap wrote

How about flooding it with water to see if water comes out the other end? Or blast it with compressed air?

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iamintheforest OP t1_jdws0cd wrote

Good idea! But...it's sealed on said other end some 60 feet away

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PublicRedditor t1_jdww6r5 wrote

Wire seven 10' lengths of rebar together and shove it through, knocking off the cap on the other end?

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iamintheforest OP t1_jdwyoe3 wrote

pvc glue ...

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PublicRedditor t1_jdx5kbx wrote

Well there's the other half of where you went wrong :). Please tell me you at least have a string already pulled through the pipe.

I have the same setup on my 20' wide patio but it's only a 2" pvc pipe. I made sure NOT to glue the caps on and TO have a string pre-run through to be able to pull anything if I do ever need to use it.

Good luck!

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iamintheforest OP t1_jdx5yyy wrote

it's open on one end. I have no trouble feeding things to the end, just need to reliably detect those things.

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jezra t1_jdwteoo wrote

I had to do something similar to trace about 1/4 mile of 2" irrigation line. The product I used was a armadatech pro290 and 150' metal fish tape. The fish tape was sent up the pipe, and the pro290 transmitter was connected to the exposed fish tape. Then I used the pro290 receiver to find where the fish tape was.

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https://armadatech.com/upcp_product/pro290/

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edit: check your local tool rental company to see if they have something similar

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zedsmith t1_jdwvcqh wrote

I rented a camera snake and locator wand at my Home Depot last Saturday— 4 hours for roughly 225 dollars.

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Wellcraft19 t1_jdwvxk1 wrote

Good move though, I also put pipes or conduits in the ground when digging. Also take photos of them with a tape measure displayed from ‘fixed’ objects.

You’ll quickly find the pipe - and will be glad you put it in 👍

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iamintheforest OP t1_jdwynnj wrote

Totally. I seem to have every photo of the trench and such, but just not where the end is! And...so many more plants and yard stuff now then when the photos were done! I am still far ahead of having to dig a new trench though, so....i'll take that win :)

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allangee t1_jdy2lde wrote

Seriously -- find a nice loud speaker that will fit in the exposed end of the pipe. Block the exposed end to muffle the sound as much as possible.

If you have a mechanic's stethoscope, great! If not, a piece of steel (like rebar) will work by placing one end against your ear. Start near where you think the other end is, then move farther and closer to determine if you're getting nearer to the end of the pipe. If you're really lucky, you'll touch the pipe itself and get a solid sound. If not, you should be able to narrow the search area quite a bit.

I'm assuming you can't see which direction the pipe is going,or that it's curved -- otherwise you would have lined up a forty foot tape measure on the surface.

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UseABiggerHammer t1_je1b8jm wrote

That speaker-and-stethoscope idea is ingenious. But if that doesn't work...

Put some kind of load that is on and drawing electricity on the end of an extension cord and poke it down all the way to the end of your pipe. You need to have something that causes current to flow down the cord. If you have a long enough cord, you could even double it so that you can have the load on the end outside of the pipe.

Call your local utility locator (usually they are free) and have them come with their detectors and mark it. A hot wire in the ground "should" come up on their device.

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