# Leak on water line in wall



## Plumbus (Aug 4, 2008)

Line was tested before sheetrock was installed. But, now it won't hold a test and we don't want to find the problem by turning on the water and possibly soaking a wall. 
Anyone familiar with sniffing out leaks in walls by charging a line with nitrogen or some other gas?


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## ROCKSTARPLUMBER (Dec 14, 2008)

Helium. You wanna use helium.


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## TerryTotoSucks (5 mo ago)

My uncle Terry would bring a propane grill tank and fill that sob up with gas and use a gas leak detector. 

My cousin Terry might use Freon and use a refrigerant detector.

You could use high pressure air or nitrogen and an ultrasonic leak detector if it’s quiet enough environment.


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## jakewilcox (Sep 3, 2019)

Helium. With a helium detector. The problem is that you have to be able to get to the space around the pipe with a helium detector. There are several types, most have an telescoping rod that works as the business end of the sniffer. I’ve been able to drill a hole in metal top plates to sniff out leaks. 

Equipco in Concord, CA will have both the gas and the sniffer for rent. 






Helium Leak Detector For Rent - Best Price Guarantee


Helium Leak Detector Rental Equipment for use in detecting Helium in any application including Soil Gas Sampling with a Helium Leak Detection Shroud.




www.equipcoservices.com





I’ve also seen it done by charging up the pipe with carbon dioxide and hitting the wall with what seemed like a sophisticated stethoscope.

Good luck!


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## TerryTotoSucks (5 mo ago)

I would want to know how bad the leak is. The worse the leak the better. 

Leak detection guy here uses nitrogen with 5-600 psi of pressure. Then puts his ears on and listens for the whistle it creates.


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## dhal22 (Jul 30, 2010)

How about high pressure air test? Like argon or nitrogen and crank up the pressure........


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## Cagey57 (Mar 2, 2018)

Is this on Pex, Copper or CPVC (hope not) ?
If you have it narrowed down to something less than 15" of vertical run I would Isolate the section in question and use 90% Isopropyl Alcohol. It's "Wet" but dries (evaporates) almost instantly.

Had to do this on Med Gas piping that got hit with a cabinet screw. You can't "water test" Med Gas piping but the AHJ allowed 90% IPA without making us replace it.


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## Blue2 (12 mo ago)

Cagey57 said:


> Is this on Pex, Copper or CPVC (hope not) ?
> If you have it narrowed down to something less than 15" of vertical run I would Isolate the section in question and use 90% Isopropyl Alcohol. It's "Wet" but dries (evaporates) almost instantly.
> 
> Had to do this on Med Gas piping that got hit with a cabinet screw. You can't "water test" Med Gas piping but the AHJ allowed 90% IPA without making us replace it.


Woah, a 90% IPA. I bet you slept good after drinking one of those


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## Plumbus (Aug 4, 2008)

Cagey57 said:


> Is this on Pex, Copper or CPVC (hope not) ?
> If you have it narrowed down to something less than 15" of vertical run I would Isolate the section in question


"If I could narrow it down to that small a section of pie, I would just open the wall and fix the problem.


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## WashingtonPlung (Jul 25, 2016)

Have you considered using nail plates before the wall was sheet rocked? 

Jokes aside how long of a run is it?
And when you say it won't hold test. Do you mean you can get it to the pressure and then it slowly loses pressure. Or you can't even reach desired PSI to start the test.


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## Plumbus (Aug 4, 2008)

We use nail plates religiously, but doing so wouldn't have stopped this one.
Pumped the line up with propylene gas (that's all I had on the QT) and narrowed the leak down to one stud bay. Opened it up and look what we found, a nail through the exterior plywood. That's why seasoned carpenters lay out the stud widths and chalk them on the plywood. Then, if they hit a pipe it's because the pipe went through a stud, or a top or bottom plate. Unfortunately, a gun nailer will penetrate a stub plate even if it's 16 ga. And, the problem with 16 ga plates is that they form a bulge in the wall covering.


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## Debo22 (Feb 15, 2015)

Here’s a close call, it was probably like that for 20 years when the guys installing a backyard patio sent a lag through















through


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## WashingtonPlung (Jul 25, 2016)

What state are you located?. Washington we can't run lines in outside walls .


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## Plumbus (Aug 4, 2008)

We can in the low lying areas of California. Not in the mountains.


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## asapmarty (Nov 19, 2012)

Plumbus said:


> We use nail plates religiously, but doing so wouldn't have stopped this one.
> Pumped the line up with propylene gas (that's all I had on the QT) and narrowed the leak down to one stud bay. Opened it up and look what we found, a nail through the exterior plywood. That's why seasoned carpenters lay out the stud widths and chalk them on the plywood. Then, if they hit a pipe it's because the pipe went through a stud, or a top or bottom plate. Unfortunately, a gun nailer will penetrate a stub plate even if it's 16 ga. And, the problem with 16 ga plates is that they form a bulge in the wall covering.


Its really difficult to shield against every possable way that another person coming behind you can damage your work. Most codes have pipes at least 1-1/4' from the edge of framing that they pass through or else shield that pipe. Commercial codes usually call for 1-1/2 " clearance. You could try to practice that clearance from sheathing that is likly to get nailed into, such as when siding is going to be attached to the sheathing. Mechanical codes require shielding for refrigerant lines that are in close proximety to underside of roof sheathing to protect from roof nails and "shiners" - sheathing nails that miss the rafters. Unwanted penetrations are going to happen. Homeowners hanging things on walls, etc. Not a big fan of using flammable gases to do leak detection. Helium can be a very expensive gas but is commonly used for leak detection in manufacturing of refrigeration products. Also, pressurizing water piping above its rating could potentially damage the pipe or its connections. Many leak detection companies fill with water and back it up with a regulated pressure of compressed air or nitrogen. Many bring air in scuba tanks. Its a quiet way to intruduce it while trying to listen for the leak. I put this info out there as something that might be helpfull to others. Not intended to talk down to anyone. We should be able to share info that some may already know, and some may not.You did the install, so you probably already had in idea where pipes you installed could be in a place that was vulnerable to a nail, etc. Good job on locating this. Wide shields are called for in most codes at top and bottom plates that pipes pass through from above or below because another may come after you and install wide moldings such as crown or tall bottom moldings.


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## Plumbus (Aug 4, 2008)

Marty
I agree with you, helium or nitrogen would be the way to go. So did my apprentice. Unfortunately, I didn't have access to either in a timely fashion on the day in question and I was working within a tight window of time. Combustibles require two things to ignite, critical mass and an igniter. Control for either or both and you greatly decrease the danger. We made sure there were no sources of a potential spark and once we located the general area of the leak, we shut down the gas and let it dissipate and carefully opened the bay with a blower going full tilt.


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## Tommy plumber (Feb 19, 2010)

Plumbus said:


> Line was tested before sheetrock was installed. But, now it won't hold a test and we don't want to find the problem by turning on the water and possibly soaking a wall.
> Anyone familiar with sniffing out leaks in walls by charging a line with nitrogen or some other gas?



You could charge up the line with a small nitrogen bottle and using your naked ear, probably hear the hissing noise.

Or, hire an electronic leak detection company. Which is essentially the same thing. He just uses a ground microphone, with an amplifier that amplifies the sound and sends it to his headphones.

After I got into elec. leak detection, I have gotten really good at sniffing out leaks.


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## Blue2 (12 mo ago)

A thermal imager is a great tool to have when trying to locate leaks. Or even a simple moisture meter.


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## Plumbus (Aug 4, 2008)

Bottom line. My method worked. It took about 4 hours to find the leak, open the stud bay, fix it and patch & tape the wall.
I'll take those results any day.


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## TerryTotoSucks (5 mo ago)

Plumbus said:


> Bottom line. My method worked. It took about 4 hours to find the leak, open the stud bay, fix it and patch & tape the wall.
> I'll take those results any day.


I’m surprised your first choice wasn’t to pump it up to a few hundred pounds of nitrogen and listen for the whistle.


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## Blue2 (12 mo ago)

Plumbus said:


> Bottom line. My method worked. It took about 4 hours to find the leak, open the stud bay, fix it and patch & tape the wall.
> I'll take those results any day.


Whatever works, but I have a background in cleaning aviation fuel tanks. I am familiar with Leo/Uel etc. personally I wouldn’t do it the way you did. I would prefer an inert gas like nitrogen or even just and air compressor if I couldn’t run the water.

This is a place for professional plumbers to shoot the breeze and trade tips etc. you do you and whatever keeps the food on your table.


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## Blue2 (12 mo ago)

TerryTotoSucks said:


> I’m surprised your first choice wasn’t to pump it up to a few hundred pounds of nitrogen and listen for the whistle.


Or even a simple air compressor. I have a 5 gal pancake in the truck for this reason


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## TerryTotoSucks (5 mo ago)

Blue2 said:


> Or even a simple air compressor. I have a 5 gal pancake in the truck for this reason


Air could very well work but I keep a bottle of nitrogen and for a leak like the OP had I would’ve pumped it up to 500-600 psi. 

If that didn’t work then no need to try an air compressor.


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## Blue2 (12 mo ago)

TerryTotoSucks said:


> Air could very well work but I keep a bottle of nitrogen and for a leak like the OP had I would’ve pumped it up to 500-600 psi.
> 
> If that didn’t work then no need to try an air compressor.


Maybe a dumb question, but have you ever damaged any fixtures or fill valves pumping it up that high? I get nervous going over 100psi


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## TerryTotoSucks (5 mo ago)

Blue2 said:


> Maybe a dumb question, but have you ever damaged any fixtures or fill valves pumping it up that high? I get nervous going over 100psi


Nope, But this job was just pipe, no fixtures installed.


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## Blue2 (12 mo ago)

TerryTotoSucks said:


> Nope. But this job was just pipe, no fixtures installed.


Makes sense, I’m thinking hooking up to a washer box or hose bib somewhere like I typically do.


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## TerryTotoSucks (5 mo ago)

Blue2 said:


> Makes sense, I’m thinking hooking up to a washer box or hose bib somewhere like I typically do.


Isolate any fixtures that you can. I typically don’t do leak detections but I have.


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## Blue2 (12 mo ago)

TerryTotoSucks said:


> Isolate any fixtures that you can. I typically don’t do leak detections but I have.


I pretty much focus on leak detection and tankless water heaters. I’ll have to try it next time I do a leak detection. Will let you know how it goes lol


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## Plumbus (Aug 4, 2008)

You both are right, air first, inert gas second. But, I was in a pinch and didn't have access to nitrogen that morning. My plumber had already tried air at 100lb+ the day before to no result (without me present). He's young with limited experience. I may have been able to make the pipe speak, but like I said, I was under the gun.


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## TerryTotoSucks (5 mo ago)




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## asapmarty (Nov 19, 2012)

TerryTotoSucks said:


> Air could very well work but I keep a bottle of nitrogen and for a leak like the OP had I would’ve pumped it up to 500-600 psi.
> 
> If that didn’t work then no need to try an air compressor.


You need to consider the pressure limitations of everything in the system that will get exposed to the test or detection pressure you are applying. 500 - 600 PSI may be acceptable in a refrigeration system, but not for most plumbing systems!


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## TerryTotoSucks (5 mo ago)

asapmarty said:


> You need to consider the pressure limitations of everything in the system that will get exposed to the test or detection pressure you are applying. 500 - 600 PSI may be acceptable in a refrigeration system, but not for most plumbing systems!


 @Tommy plumber does the same thing.


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## Tommy plumber (Feb 19, 2010)

TerryTotoSucks said:


> @Tommy plumber does the same thing.




I do indeed use an intert gas {nitrogen} but at most I am around 30-40 psi. My regulator steps pressure way down from the bottle pressure.


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## TerryTotoSucks (5 mo ago)

Ok, no problem. I still pump it up to 500 psi when I’m trying to make a leak whistle. I’m speaking of copper tube, not plastics.

I just isolate the fixtures by turning valves off if
Possible. If not possible I let it rip anyway.

My bottle pressure is in the thousands…..not sure exactly. I think it’s 2500 psi. I posted a pic of my gauge and bottle.

I just googled nitrogen bottle pressure and it’s between 2200-2400 psi.


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## Tommy plumber (Feb 19, 2010)

TerryTotoSucks said:


> Ok, no problem. I still pump it up to 500 psi when I’m trying to make a leak whistle. I’m speaking of copper tube, not plastics.
> 
> I just isolate the fixtures by turning valves off if
> Possible. If not possible I let it rip anyway.
> ...



I do lots of electronic leak detection and I will sometimes put nitrogen in the copper lines. But with the pressure that you're talking about, the leak must really whistle quite loud. I had never thought of that pressure. You must go through a lot of nitrogen that way. I just have a small nitrogen bottle on my van; its about the size of an acetylene B tank.


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## TerryTotoSucks (5 mo ago)

Tommy plumber said:


> I do lots of electronic leak detection and I will sometimes put nitrogen in the copper lines. But with the pressure that you're talking about, the leak must really whistle quite loud. I had never thought of that pressure. You must go through a lot of nitrogen that way. I just have a small nitrogen bottle on my van; its about the size of an acetylene B tank.


I use to call a company named American Leak Detection. The guy was from Louisiana. He would locate slab leaks for me when the plan was to repair the pipe vs repipe through the attic with Pex. 

That’s who turned me on to the high pressure. He would put on his listening device and if he couldn’t hear the leak good at 100-150 psi He would keep cranking it up to 500 psi.

I would turn the regulator for him, he would hold his thumb up or down and I would throttle up the pressure as he listened.
He was usually with 3’ of the leak. We did this probably once a month for about 5 yrs. Then he retired. 

So I have an old analogue listening device that I’ve used on a few occasions to find leaks under slabs. When he retired I decided to just bypass most all leaks. I became very good at locating manifolds and finding the leaking pipe to bypass.


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## Tommy plumber (Feb 19, 2010)

TerryTotoSucks said:


> I use to call a company named American Leak Detection. The guy was from Louisiana. He would locate slab leaks for me when the plan was to repair the pipe vs repipe through the attic with Pex.
> 
> That’s who turned me on to the high pressure. He would put on his listening device and if he couldn’t hear the leak good at 100-150 psi He would keep cranking it up to 500 psi.
> 
> ...




I don't want to judge the Amer. Leak Detection man who retired, but I am wondering if he needed that high pressure to compensate for low-quality listening equipment. I have leak detection equipment that lists for $3500 and I can usually get right on top of the slab leak. Once in a while I am a foot off. 

I also use an infra red {IR} camera to look for leaks on hot lines under the slab. I have even re-routed hot water into a cold manifold to temporarily turn the cold manifold 'hot' for my investigation.


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## Tommy plumber (Feb 19, 2010)

Red 'X' is my electronic leak detection mark and then you see the repair.

I was about a foot off on this one.


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## Tom F Ohio (6 mo ago)

Tommy plumber said:


> Red 'X' is my electronic leak detection mark and then you see the repair.
> 
> I was about a foot off on this one.


Do the cinch clamps that you use fit snug on the pipe. The new ones that their selling around here at the supply house are real loose.


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## TerryTotoSucks (5 mo ago)

Tommy plumber said:


> I don't want to judge the Amer. Leak Detection man who retired, but I am wondering if he needed that high pressure to compensate for low-quality listening equipment. I have leak detection equipment that lists for $3500 and I can usually get right on top of the slab leak. Once in a while I am a foot off.
> 
> I also use an infra red {IR} camera to look for leaks on hot lines under the slab. I have even re-routed hot water into a cold manifold to temporarily turn the cold manifold 'hot' for my investigation.


This was 25 yrs ago. He used nitrogen to make the pinhole leak louder. Some leaks are very small. I have no idea of the brand listening equipment. Also there can be noise in the environment that you can’t control.

Yes, putting hot water through the cold side is a option we’ve used before, good tactic.

We can’t make joints under the slab unless it’s brazed. Not even repairs. If it’s cpvc or pex it’s an automatic bypass because there’s no joints allowed under slabs unless it’s brazed rule kicks in.

Funny that his name was Tommy also ! 🤣


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## Tommy plumber (Feb 19, 2010)

Tom F Ohio said:


> Do the cinch clamps that you use fit snug on the pipe. The new ones that their selling around here at the supply house are real loose.



I dont cinch clamps, those are crimp rings.

And technically we are not supposed to soft solder under a slab either......Shhhhhhhhh. LOL.


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## TerryTotoSucks (5 mo ago)

Tom F Ohio said:


> Do the cinch clamps that you use fit snug on the pipe. The new ones that their selling around here at the supply house are real loose.


I’ve been using Sioux Chief crimp rings. Real happy with them. I buy them in bulk from Pex Universe


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## skoronesa (Oct 27, 2015)

Tommy plumber said:


> I dont cinch clamps, those are crimp rings.
> 
> And technically we are not supposed to soft solder under a slab either......Shhhhhhhhh. LOL.


I don't understand why you used pex at all here. If you're okay with those two solder joints why not just use a short piece of copper and two couplings?

Also, you may have made pinholes more likely to occur again by introducing a dielectric material. What did the inside of the pipe look like?


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## Tommy plumber (Feb 19, 2010)

skoronesa said:


> I don't understand why you used pex at all here. If you're okay with those two solder joints why not just use a short piece of copper and two couplings?
> 
> Also, you may have made pinholes more likely to occur again by introducing a dielectric material. What did the inside of the pipe look like?



I wanted to test out pex in that application.

Brass and copper can touch all day long. Galvanized steel can't touch copper....that's a no-no in our code.

People are usually given {3} options:
1} spot repair,
2} re-route the line over-head;
3} whole-house re-pipe.

I can guide them but it's their call.
I have a whole-house re-pipe coming up in January.


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