# Any advice on slab leak, a.s.a.p, please



## RealLivePlumber (Jun 22, 2008)

I have a customer who has a hot water distribution pipe leak, under a concrete floor (slab on grade home). I do not have much experience in this, as not too many slab homes around here. 

I got the call last night. Upon arrival, there was some mud on top of the carpet in the right corner of the living room, at the exterior wall, and some bubbling. The water heater and bathroom are 20' away. I can hear water hissing in the bathroom. I pulled the access panel behind the tub, and the earth shows, but it's not really wet there. 

Any advice? I gotta go back to check it out tomorrow.


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## Optimus Primer (May 20, 2009)

call a leak locating company if you dont have the equipment. They can pin point exactl where it's at.


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## gladerunner (Jan 24, 2009)

hot water you can sometime find with infared thermomater, look for hotest temp of slap


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## SlickRick (Sep 3, 2009)

RealLivePlumber said:


> I have a customer who has a hot water distribution pipe leak, under a concrete floor (slab on grade home). I do not have much experience in this, as not too many slab homes around here.
> 
> I got the call last night. Upon arrival, there was some mud on top of the carpet in the right corner of the living room, at the exterior wall, and some bubbling. The water heater and bathroom are 20' away. I can hear water hissing in the bathroom. I pulled the access panel behind the tub, and the earth shows, but it's not really wet there.
> 
> Any advice? I gotta go back to check it out tomorrow.


I have the equipment to trace metal lines out and a Fisher XLT 30 for sound. You are going to have to be able to listen to the leak, best way I know of is to shut down the pressure and feed air into the lines. The sound of the air escaping makes a distinct sound. Before I went Hi-Tech I found a few with air and a stethoscope, if it is not too deep. Or you could do the helium tech. I am not set up to do that.


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## SlickRick (Sep 3, 2009)

Or you could locate the manifolds,isolate the line and reroute the damaged line overhead. Seems to be very popular these days.


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## Phat Cat (Apr 1, 2009)

slickrick said:


> Or you could locate the manifolds,isolate the line and reroute the damaged line overhead. Seems to be very popular these days.


That is how we do it. Customers are appreciative of not tearing up their flooring.

We were not experienced with slab leaks until we moved here. Twice we hired a 'leak detection' specialist, two different cos., and neither was accurate enough for our comfort. One was 8' off and in a different room.


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## PlungerJockey (Feb 19, 2010)

We do alot of slab leaks, a leak on the hot water side can be repaired without a jackhammer or leak detection equipment.

Turn the water supply off to the waterheater, so the water will stop running and everything will cool down.

If you can hear the leak, then you will have a pretty good idea as to where to start looking. Cut some holes in the walls at manifold locations. Turn the hot water back on and feel for water running thru the manifold, it'll be hotter than the others.

If it's a 1/2 inch line cut it at each end of the loop and sweat on 1/2 x 3/8 compression fittings. Get some 3/8 inch pex and push it thru the 1/2 inch copper and connect it. If the pex will not push thru the copper, you can split it in half back about 10 feet. The smaller diameter will make it easier to push and once you get the split side thru you can pull it with channel locks. I have not found one yet I could not pull pex thru. If it's a 3/4 line use 1/2 inch pex. 

Also be sure to install a expansion tank and a PRV to keep everything in check and prevent you lines from blowing apart.

Slableaks have became such a problem here that we would bust up the floor and repair one only to return and repair a leak 3 feet from where we made the original repair. Running pipe overhead is not prferred here because of freezing temps in the winter.

Good Luck


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## RealLivePlumber (Jun 22, 2008)

Thanks everyone.

I did a couple a few years back, before 3/8" pex was around. I managed to get 3/8" od copper thru a 1/2"line. 

I don't think there are manifolds. Gotta look a little closer tomorrow. I talked to another local plumber, and he thinks he remembers joints underground in this community. Just great.

Anyway, I remembered I have an electronic stethoscope from my machinist days. I played around with it today, and that might be a help. I was planning on taking the tag along compressor, and airing up the hot side. 

I think it's a pretty big leak, judging from the sound in the bathroom, and the amount of water in the living room. ( I think I'll check the clock on the water meter, as well) But where the most water shows, there is no reason for water piping to be at that location. 

Thanks again, I'll let you all know. 

(BTW, I have not heard of any really good leak detection co.'s in the area.) ( I don't wanna show up with some schmo, and look like an idiot. I'm pretty good at that all by myself:laughing


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## Richard Hilliard (Apr 10, 2010)

*slab leaks*

Turn the thermostats on the heater up all the way and throttle the incoming valve down on the water hater and this will create steam and a very hot spot on the floor where the pinhole is located. Usually this takes an hour to two hours to locate the leak.

I have located the manifolds in the past and rerouted the water line.I am not a fan of decreasing volume by deceasing the pipe size unless it is to one individual fixture and not a bathroom group.


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## Protech (Sep 22, 2008)

That is exactly how I roll. My hat is off to you sir 



PlungerJockey said:


> We do alot of slab leaks, a leak on the hot water side can be repaired without a jackhammer or leak detection equipment.
> 
> Turn the water supply off to the waterheater, so the water will stop running and everything will cool down.
> 
> ...


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## Associated Plum (Nov 4, 2008)

Protech said:


> That is exactly how I roll. My hat is off to you sir


To everyone that is pulling a smaller line in an existing line under the slab. What code are you using that this is approved in?

On most slabs the lines are already at the minimum pipe size and then your reducing them even more. I would expect this from a handyman and not Plumbers, although I have seen where licensed plumbers here have done the same thing and it makes the client upset when they have another leak and we tell them that we can not do it like that.

Sell the repipe and be done with it.


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## njoy plumbing (May 19, 2009)

Were running into jobs that had hacks syuch as the concrete guys running these lines before they pour. Sometimes even branching under the slab. Its a little frustrating but they now look to us to save the day.:thumbup:


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## Protech (Sep 22, 2008)

Yes, it would be against code to do that but it is just a repair for a customer who is too cheap to do a repipe. I always explain to them that it is a lower cost "rig" and is not the right way but it will work. I also always explain that there will be a reduction in flow pressure in some of the fixtures. It's their house, they make the call.



Associated Plum said:


> To everyone that is pulling a smaller line in an existing line under the slab. What code are you using that this is approved in?
> 
> On most slabs the lines are already at the minimum pipe size and then your reducing them even more. I would expect this from a handyman and not Plumbers, although I have seen where licensed plumbers here have done the same thing and it makes the client upset when they have another leak and we tell them that we can not do it like that.
> 
> Sell the repipe and be done with it.


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## pauliplumber (Feb 9, 2009)

Associated Plum said:


> To everyone that is pulling a smaller line in an existing line under the slab. What code are you using that this is approved in?
> 
> On most slabs the lines are already at the minimum pipe size and then your reducing them even more. I would expect this from a handyman and not Plumbers, although I have seen where licensed plumbers here have done the same thing and it makes the client upset when they have another leak and we tell them that we can not do it like that.
> 
> Sell the repipe and be done with it.


When doing service/repair, sometimes solving the problem, even if it's not an optimal solution, takes priority over satisfiying the code.

Perhaps a repipe was not an option. Everything is situational.


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## Don The Plumber (Feb 14, 2010)

Protech said:


> Yes, it would be against code to do that but it is just a repair for a customer who is too cheap to do a repipe. I always explain to them that it is a lower cost "rig" and is not the right way but it will work. I also always explain that there will be a reduction in flow pressure in some of the fixtures. It's their house, they make the call.



Until they sell the house, to the next unsuspecting victim.

But I have to admit, I've done it. People simply don't have the funds to do a repipe, & if you don't do it, someone else will. 99.99999999999% of the time, people will never notice a flow reduction. The 1/2" line will still supply more water, to say a bathroom group, than they could possibly use.
Last house I did this to was, they had 1/2 supplies to water heater, it was superbowl sunday, & was my insurance agents 80 yr old mother living there alone. A repipe would cost about as much as the house is worth. ( Simply put, it was just not practical) & I never even mentioned the issue to her.:no:


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## gear junkie (Jun 20, 2008)

Associated Plum said:


> To everyone that is pulling a smaller line in an existing line under the slab. What code are you using that this is approved in?
> 
> On most slabs the lines are already at the minimum pipe size and then your reducing them even more. I would expect this from a handyman and not Plumbers, although I have seen where licensed plumbers here have done the same thing and it makes the client upset when they have another leak and we tell them that we can not do it like that.
> 
> Sell the repipe and be done with it.


Couldn't say it better myself.


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## Tommy plumber (Feb 19, 2010)

*Slab leaks*

I have repaired slab leaks by either: 1) running a new line overhead or 2) opening floor and repairing leak under slab. By code, any joint under slab shall be brazed (silver soldered). Running line overhead is preffered, in my opinion. But freezing Jersey temps in Winter might not allow. Usually I ran a new line overhead due to a wooden stake being driven through a waterline after the ground rough (1st rough) by masons forming for the recessed garage. While trying to pump up water piping for 2nd rough inspection, I wasn't able to get pressure to hold and that is how I knew I had a leak under slab. As already posted, with a leak on hot side, hike up t-stats and feel with bare feet for hot spot on slab. Either way add up material, estimate carefully your time, add a contingency fee (typically 5%) and book the call. All the best- keep us posted.


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## RealLivePlumber (Jun 22, 2008)

So yesterday we went back over. I found the location of the tubing with the SR20. The leak was showing at the exterior wall, 3 feet away from the lines. We put air in the system, and air showed at the same place. We broke the floor, and my locate and depth were 100% accurate, to the inch :thumbsup: (1'6" deep) 

So, I had air leaking into the excavation, but can't find leak from the pipe. We peel back the rest of the carpet, and run more air. Now I can hear bubbling about 4' away, in the center of the room, by putting my ear to the slab. But it's about a 3' diamater area. So it's about 90 degrees in there from the restoration co's dehumidifier. And I'm beat and don't feel like breaking any more concrete unnecessarily. I called American leak. He is actually right in the area. (His office is about 30 miles away.) He comes right over, and tells me he agrees with me. His depth was 6" too deep, according to his locator. 

We break another 1' dia hole. We were right on top of it. Sweet. Used 2) 5/8 o.d. flare couplings, then repaired the concrete. I guess we had about 8 hours in the whole deal, with running to get the couplings, and concrete mix. 

I think I would have done better to lower the air pressure. I was pushing 100 psi, and I think lower pressure would have helped me more accurately hear the air thru the slab. 

The copper tube had a 1/8" to 3/16" hole in it, pointing straight down. And a bunch of those green bubbles that Pro Tech always gets. (I guess it's only a matter of time)

Anyways, thanks for all the info, and slab leaks suck.


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## Tommy plumber (Feb 19, 2010)

Real Live, was it profitable? How much did you charge, if you don't mind my asking?


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## TheMaster (Jun 12, 2009)

RealLivePlumber said:


> So yesterday we went back over. I found the location of the tubing with the SR20. The leak was showing at the exterior wall, 3 feet away from the lines. We put air in the system, and air showed at the same place. We broke the floor, and my locate and depth were 100% accurate, to the inch :thumbsup: (1'6" deep)
> 
> So, I had air leaking into the excavation, but can't find leak from the pipe. We peel back the rest of the carpet, and run more air. Now I can hear bubbling about 4' away, in the center of the room, by putting my ear to the slab. But it's about a 3' diamater area. So it's about 90 degrees in there from the restoration co's dehumidifier. And I'm beat and don't feel like breaking any more concrete unnecessarily. I called American leak. He is actually right in the area. (His office is about 30 miles away.) He comes right over, and tells me he agrees with me. His depth was 6" too deep, according to his locator.
> 
> ...


Flare couplings...WTF:blink:


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## ToUtahNow (Jul 19, 2008)

RealLivePlumber said:


> So yesterday we went back over. I found the location of the tubing with the SR20. The leak was showing at the exterior wall, 3 feet away from the lines. We put air in the system, and air showed at the same place. We broke the floor, and my locate and depth were 100% accurate, to the inch :thumbsup: (1'6" deep)
> 
> So, I had air leaking into the excavation, but can't find leak from the pipe. We peel back the rest of the carpet, and run more air. Now I can hear bubbling about 4' away, in the center of the room, by putting my ear to the slab. But it's about a 3' diamater area. So it's about 90 degrees in there from the restoration co's dehumidifier. And I'm beat and don't feel like breaking any more concrete unnecessarily. I called American leak. He is actually right in the area. (His office is about 30 miles away.) He comes right over, and tells me he agrees with me. His depth was 6" too deep, according to his locator.
> 
> ...


For what it's worth, I usually drill a 5/16" hole through the slab before breaking the floor if I am not 100% on my locate. It takes less than a minute to see if the bit comes back wet and the patch is a squirt of silicone.

Mark


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## RealLivePlumber (Jun 22, 2008)

Thanks Mark. This thing poured water for 8 hours the day before. It was ALL wet. There was 2 inches of water on the living room carpet. Literally. It was bubbling up at the exterior wall, like a spring. 

I know I shouldn't, but here goes. TM, what are you referring to in your statement in reference to the flare couplings?


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## brass plumbing (Jul 30, 2008)

a manifold will supply 1/2 copper to the chrome angle under the slab, the angle valve has a 3/8" supply to the hot side of the fixture.
if a 3/8" line is fed thru the copper then what's the difference?
i see their point why can't you?


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## ToUtahNow (Jul 19, 2008)

RealLivePlumber said:


> Thanks Mark. This thing poured water for 8 hours the day before. It was ALL wet. There was 2 inches of water on the living room carpet. Literally. It was bubbling up at the exterior wall, like a spring.
> 
> I know I shouldn't, but here goes. TM, what are you referring to in your statement in reference to the flare couplings?


After you have drilled a couple of holes, the hole with the highest spout is closets to the leak. It really is amazing to watch how holes further away slowed down as you open holes closer to the leak. With my Metrotech I don't have to do it but more than once I had to with my Goldak.

Mark


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## Redwood (Sep 8, 2008)

slickrick said:


> Or you could locate the manifolds,isolate the line and reroute the damaged line overhead. Seems to be very popular these days.


Except in Jersey overhead repipes are not an option that is acceptable in the November through March period of the year...


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## Protech (Sep 22, 2008)

Pex with recirc system with heaters and insulate all lines with 1" walled closed cell polyethylene insulation?

Seams like it would work........dunno though. Never plummed up north:001_unsure:



Redwood said:


> Except in Jersey overhead repipes are not an option that is acceptable in the November through March period of the year...


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## Redwood (Sep 8, 2008)

Protech said:


> Pex with recirc system with heaters and insulate all lines with 1" walled closed cell polyethylene insulation?
> 
> Seams like it would work........dunno though. Never plummed up north:001_unsure:


Lets just say...
What do you think the chances are for a hydronic loop of a boiler freezing in an attic?

I've seen it...

You might stand a little better than a snowballs chance in hell if you did not apply insulation to the pipe and ran it directly on top of the sheetrock ceiling then insulating over it...

Up here it's just wise not to put any plumbing in exterior walls and attics...

The insulation and recirculation is a nice touch but I wouldn't plumb with it's operational reliability hanging over my head...
Pumps crap out...
People turn valves without knowing what they do...
Ice storms and blizzards make power outages happen...

Then of course we know hot water freezes before cold water will...:whistling2:


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## GREENPLUM (Jul 27, 2008)

Isn't cold water heavier than hot water


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## Redwood (Sep 8, 2008)

GREENPLUM said:


> Isn't cold water heavier than hot water


Water is its heaviest just before it freezes...

Why?


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## GREENPLUM (Jul 27, 2008)

Redwood said:


> Water is its heaviest just before it freezes...
> 
> Why?


 
so cold water is heavier than hot water 

why you ask? I am tryin to fix a oil leak in the gulf :laughing:


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## Redwood (Sep 8, 2008)

GREENPLUM said:


> so cold water is heavier than hot water
> 
> why you ask? I am tryin to fix a oil leak in the gulf :laughing:


Oh Okay...:laughing:

There ain't no fixin that...

Drill Baby Drill....:laughing:


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