How To Know Where Your Underground Pipes Are Located?

[NullQwerty]

Hey folks,

I've got a leak in one of my return lines (the deep end line).

I've got about 4 feet of concrete surrounding the pool. Outside of the concrete is all dirt. My hope is that when they laid the piping for the pool, they ran it under the dirt as much as possible and tried to avoid the concrete, so that if there ever was a leak, you might be able to repair it without tearing up the whole deck.

So, two questions:
1) Do they often do that (i.e. go out of the way to avoid the concrete)?

2) Is there a way to determine where the pipe is laid down (without tearing up the concrete or the surrounding lawn)? I can't think of anyway, but I can't be the first person that needs to figure this out, so...

Here's a picture of what I am talking about:

 

[JasonLion]

There is no easy way to know where the pipes are. The most common approach is for the pipe to be under the deck, but different builders do it different ways.

It is also possible that the pipe was run directly under the pool.

 

[NullQwerty]

Thought so. I was hoping that flexible pvc was lined with metal that could be traced with a metal detector or something.

Ok...then in that case if I dig up the lawn and don't find it, I should just be able to run a whole new line using the path I suggested in the pic, right? Only difficult part would be getting it under the 4 foot section of concrete, but I'm sure with a little creatvity it's possible.

Is this what you guys would do?

Note: even if the new line were to cause the concrete to sink or crack doing it this way, I wouldn't be too upset because it already has some sinking and cracking.

Thanks as always for the help!

 

[waste]

Hey, Null

You might want to look into renting some geophones, although I'm not sure where you would go to rent them

"Waste", you say,"what in the blue blazes are geophones?" Geophones are 2 metal discs comprised of an 'oreo' of 2 disparate metals (like brass/ copper/ brass) attached to stethoscope earpieces. They amplify small sounds and are used to detect underground leaks (they are very sensitive - the old saw goes that you can hear an ant f*rt :lol: ) All the pool companies I've worked for have had a pair, even though we rarely use them, so you might see if a local pool company would rent you theirs for a Sunday

While it's kind of 'hit or miss' on detecting the actual leak, if someone tapped on the pipes while you were listening through them, you should be able to at least find where the pipes run - and maybe even be able to hear the leak itself 8)

If you can find a pair, let me know and I'll pass along a couple of tips on using them

 

[wmshay6]

You could try dowsing for the underground lines. I know I know it sounds like voo doo- i refused to believe it either until I tried it:

Take two long lengths of wire 36 " or so. I cut metal coat hangers and straightened them. Then bend the end about 6" in, forming an "L". The key is that both of the long legs be the same length. Then hold the short six inch end in your closed hands with the long ends pointing straight out from your body -shoulder width apart. Holding the wires loosely, walk SLOWLY in a direction you think is perpendicular to the pipes. When you cross over the water filled pipes, the wires will cross over themselves in front of your body.

I didn't believe it either till I tried it. Now it's my favorite pool party trick for non believers!

 

[NullQwerty]

You could try dowsing for the underground lines. I know I know it sounds like voo doo- i refused to believe it either until I tried it:

Take two long lengths of wire 36 " or so. I cut metal coat hangers and straightened them. Then bend the end about 6" in, forming an "L". The key is that both of the long legs be the same length. Then hold the short six inch end in your closed hands with the long ends pointing straight out from your body -shoulder width apart. Holding the wires loosely, walk SLOWLY in a direction you think is perpendicular to the pipes. When you cross over the water filled pipes, the wires will cross over themselves in front of your body.

I didn't believe it either till I tried it. Now it's my favorite pool party trick for non believers!

Ok...Now that I have to try just for the fun of it I've seen it on tv so I know what you're talking about

 

[duraleigh]

You could try dowsing for the underground lines.

Well, that's the most ridiculous thing I have ever heard of...........however, it works. Here in NC, it's not uncommon to pay a "witch" to find your best spot for a well.

The best one I ever say was a guy who came to our house to locate underground phone wires, electrical, etc. for a dig we wanted to do,

After locating the wire with thousands of dollars worth of very sophisticated electronics, he located a drain pipe (that I knew the location) with the two lengths of a coathanger. He stopped absolutely right on top of the drain pipe....couldn't have been off by more than five inches.....it was amazing.

He charged outrageously for the wire location but did the drainpipe for free!!

 

[duraleigh]

Null,

Back on topic, how do you know you have a pressure side (return line) leak?

 

[NullQwerty]

Hey, Null

You might want to look into renting some geophones, although I'm not sure where you would go to rent them

"Waste", you say,"what in the blue blazes are geophones?" Geophones are 2 metal discs comprised of an 'oreo' of 2 disparate metals (like brass/ copper/ brass) attached to stethoscope earpieces. They amplify small sounds and are used to detect underground leaks (they are very sensitive - the old saw goes that you can hear an ant f*rt :lol: ) All the pool companies I've worked for have had a pair, even though we rarely use them, so you might see if a local pool company would rent you theirs for a Sunday

While it's kind of 'hit or miss' on detecting the actual leak, if someone tapped on the pipes while you were listening through them, you should be able to at least find where the pipes run - and maybe even be able to hear the leak itself 8)

If you can find a pair, let me know and I'll pass along a couple of tips on using them

Hey Waste

It's definitely worth a shot asking around! I'll give all the local pool stores a call.

Thanks for the tip!

 

[NullQwerty]

Null,

Back on topic, how do you know you have a pressure side (return line) leak?

Hey duraleigh!

I was losing about 2 inches of water a night. So, I first replaced the seal assembly in my pump as that was leaking, but I still had the issue. So then I left the equipment off for a few days and didn't have any water loss. So then I set my multi-valve to only use the shallow end return line and didn't have any water loss. I then switched it to just use the deep end return line, and that's when I lost 2 inches of water again.

For now I'm only using the shallow end return, and to be honest...it's not that bad this way. I've got an 18X36 IG Vinyl, and surprisingly the water looks pretty good. But running it this way makes the pressure on the filter be nearly double, so I don't know how long I can get away with it doing it this way, so I figured I should probably fix it if I can.

 

[chrisexv6]

Can always do what I did: run a brand new line.

I had a return side leak in our shallow end return plumbing. It was just a LOT easier to run a new line than try to find and repair the old. The only concrete work that was necessary was a 1.5' square where the return is located, about 1' back from the edge of the pool wall. Then I rented a Ditch Witch to do the new trench in the grass, and used a large diameter PVC to go from dirt, under the concrete deck and to the return jet in the pool wall (HINT: run your garden hose in the PVC once its started in the ground, it will slowly erode the dirt out enough you can get under the concrete to the pool).

Not the easiest thing in the world, but it wasnt impossible. The nice thing is that I know about where the new line is, so I could always fix it if need be instead of running a new one.

Another suggestion I have is to get GOOD clamps to hold the new hose onto the return jet. Best I found, oddly enough, were at a marine supply store. They had twice as many "notches" in them as the HD/Lowes specials, so you could get a LOT of holding power out of them.

 

[sevver]

Hey, Null

You might want to look into renting some geophones, although I'm not sure where you would go to rent them

"Waste", you say,"what in the blue blazes are geophones?" Geophones are 2 metal discs comprised of an 'oreo' of 2 disparate metals (like brass/ copper/ brass) attached to stethoscope earpieces. They amplify small sounds and are used to detect underground leaks (they are very sensitive - the old saw goes that you can hear an ant f*rt :lol: ) All the pool companies I've worked for have had a pair, even though we rarely use them, so you might see if a local pool company would rent you theirs for a Sunday

While it's kind of 'hit or miss' on detecting the actual leak, if someone tapped on the pipes while you were listening through them, you should be able to at least find where the pipes run - and maybe even be able to hear the leak itself 8)

If you can find a pair, let me know and I'll pass along a couple of tips on using them

Using these, if you could pressurize the pipe, you would definately hear the leak. I have seen them used by leak detection companies to find watermain breaks for us. Our method was usually to dig a hole, find the pipe and see which way the water was coming from. Which is easy with watermain, not with a drain. If the drain was big enough, we would camera it, which could show a crack, but it also had a locator, which we could follow with a wand, thus tracing the pipe.

 

[sevver]

You could try dowsing for the underground lines. I know I know it sounds like voo doo- i refused to believe it either until I tried it:

Take two long lengths of wire 36 " or so. I cut metal coat hangers and straightened them. Then bend the end about 6" in, forming an "L". The key is that both of the long legs be the same length. Then hold the short six inch end in your closed hands with the long ends pointing straight out from your body -shoulder width apart. Holding the wires loosely, walk SLOWLY in a direction you think is perpendicular to the pipes. When you cross over the water filled pipes, the wires will cross over themselves in front of your body.

I didn't believe it either till I tried it. Now it's my favorite pool party trick for non believers!

We used this too, it does work, but not always. I have dug and found nothing, but I have also had it be quite accurate. Really any sort of pipe too, plastic, cast iron, clay, doesn't matter. Some people swore by using copper wires, but anything works. I always used either the metal from the locating flags, or bailing wire, or welding rod with the flux knocked off.

 

[waste]

Rhabdomancy? Come on guys

Here is The Straight Dope on 'water witching'

If you loose a tooth do you put it under the pillow for the Tooth Fairy? :lol:

 

[JohnT]

It's simple: Look at your pool and ask yourself "Where is the worst place it could be?" That's where it is.

 

[tphaggerty]

I had the exact same problem. I pressurized the line (using a pressure tester you can buy at home depot, etc - be careful, it can blow out of the pipe!!!) and we heard air escaping right at the return fitting (behind the pull wall, under the concrete, of course). We had flex PVC with no joins.

Anyway, after trying to contact my PB and not getting anywhere, I finally decided to fix it myself. Rented a concrete saw and an electric jackhammer. Was quite apprehensive about it. The saw was quite easy to use. Cut an 18" square around the top of the return, used the jackhammer to break out the concrete, then scooped out all of the dirt & gravel. Sure enough, it was leaking at one of the pipe joins in the return fitting.

I tried to fix it by tightening the collar to the return - BIG MISTAKE - as I broke the fitting at the wall. I had to replace the fitting (pull the liner from the wall, work the new fitting down - it was actually the hardest part of the job as I could not get more than 12" or so of the liner to come out of the liner track). Replaced the fitting & reglued with high strength glue. So far, everything is great. I have left the hole open (with a cover) for right now, I'm going to wait a good long time before I patch the hole permanently. I can do some pictures if you would like to see the hole and completed repair.

 

[NullQwerty]

I had the exact same problem. I pressurized the line (using a pressure tester you can buy at home depot, etc - be careful, it can blow out of the pipe!!!) and we heard air escaping right at the return fitting (behind the pull wall, under the concrete, of course). We had flex PVC with no joins.

Anyway, after trying to contact my PB and not getting anywhere, I finally decided to fix it myself. Rented a concrete saw and an electric jackhammer. Was quite apprehensive about it. The saw was quite easy to use. Cut an 18" square around the top of the return, used the jackhammer to break out the concrete, then scooped out all of the dirt & gravel. Sure enough, it was leaking at one of the pipe joins in the return fitting.

I tried to fix it by tightening the collar to the return - BIG MISTAKE - as I broke the fitting at the wall. I had to replace the fitting (pull the liner from the wall, work the new fitting down - it was actually the hardest part of the job as I could not get more than 12" or so of the liner to come out of the liner track). Replaced the fitting & reglued with high strength glue. So far, everything is great. I have left the hole open (with a cover) for right now, I'm going to wait a good long time before I patch the hole permanently. I can do some pictures if you would like to see the hole and completed repair.

Hey!

Thanks for the response! I'd love to give this a shot! I wasn't aware of the pressure test and unfortunately, so far all the local pool stores I've called don't rent geophones. So for right now I have the return line blocked and was planning to re-address the issue this weekend.

And...I'm actually lucky in that the concrete right above the return line is actually already cut out!!! 12X12 hole. It's filled with compacted dirt, but if I needed to get to it, I could!

If you have the time and don't mind me asking...could you elaborate a bit on the pressure test part of the process? I've never worked with one before. Would I blow out the line first or should it be filled with water? Do I plug the fitting in the pool wall? What are the steps/how do you do it? Also...if you don't mind...you mentioned that you could blow out the line...were there steps or measures you took to prevent this?

Thanks a lot!

 

[98xc600]

Have you tried calling a electric or pluming company? Some larger shops have locator's for finding Utilities. All they have to do is push a metal fish tape into your return and hook it up to the locator.

 

[Guest]

You could try dowsing for the underground lines. I know I know it sounds like voo doo- i refused to believe it either until I tried it:

Take two long lengths of wire 36 " or so. I cut metal coat hangers and straightened them. Then bend the end about 6" in, forming an "L". The key is that both of the long legs be the same length. Then hold the short six inch end in your closed hands with the long ends pointing straight out from your body -shoulder width apart. Holding the wires loosely, walk SLOWLY in a direction you think is perpendicular to the pipes. When you cross over the water filled pipes, the wires will cross over themselves in front of your body.

I didn't believe it either till I tried it. Now it's my favorite pool party trick for non believers!

Don't laugh!

I had a hydrogeologist recommend where to dig my well only to have deep low producing well.

I then had a well witcher come out and she gave me two locations. That was two years ago. I lost all the markings and called her out again. She found the same places and I know she did not remember where she had done them because I have logging done on the lot.

About to drill, I will let you know what we find.

 

[NullQwerty]

Have you tried calling a electric or pluming company? Some larger shops have locator's for finding Utilities. All they have to do is push a metal fish tape into your return and hook it up to the locator.

No, but actually you know what...This gives me an idea. I run a fish tape through the line and use my nephews metal detector to try to find it! If my concrete doesn't have the iron bars in it, this might work.

Still curious on the pressure test though...that might be the answers to all the problems if I can hear the leak without the geophones. Or if I pressurized it and could see it...maybe at the return fitting if I dug that up.

Worse comes worst I'll just run a whole new line myself as chrisexv6 did.