Electronic technology makes leak detection more ACCURATE

Water leaks can be a homeowner’s nightmare.  Many times, water will leak behind tough surfaces like tile or concrete that do not reveal the exact leak location.  Without a “magic lens” to find the location of the leak, you could be left to break up dozens of square feet of tile just to find a pinhole leak!

Amazingly, there are devices that “see through” tile and concrete to reveal the exact location of a water leak.  One is called an acoustic water leak detector, a device that helps you find water leaks easily and non-invasively.  This video shows some good use of the technology.  It avoids “potholing”, which is the practice of uncovering the length of pipe without any other aids to find the leak.  Acoustic water leak detection utilizes a very sensitive microphone that picks up the sounds that a leak makes as the water comes out of the pipe.  In pressurized pipes, the sound of a leak is pitched low and has a baritone or “hollow” sound, which comes from the vibration of the leak as it travels down the pipe. Leak detection professionals listen for this distinctive hollow tone because it is almost always present in leaking pipes pressurized at 30 psi and above. (Acoustic Leak Detection: How Does It Work?) Residential home water pressure is usually at least 35psi, so this technology works for homes.  

This is great news.  In the shower that I tiled in 2018, I intentionally made a removable panel behind the showerhead piping, so that any leaks could be easily accessed.  However, the source water pipes themselves are copper incased in the home’s concrete slab.  If they ever leak it would be a big chore to find the spot!  Knowing about this technology, however, is comforting.  It could have been a big help when I had a leak in the supply pipe to my previous home from my water meter in 2017.  In that case, workers dug up the whole line and replaced it.

Acoustic water leak detectors aren’t cheap: they range from about $750 to over $1000.  This one seems to have a high degree of accuracy.  It has 2 modes for leak detection: a general mode which enables the user to cover a larger area and find the general area where the leak is, then a locating mode, which helps to pinpoint the leak.  Note: although some businesses call their equipment or business “sonar” technology, it’s actually not sonar, which would send out waves of energy to see what bounces back.  Acoustic leak detection is just a really sensitive microphone.  Even in this video, the underwater probes used in the pool are still just microphones, not sonar devices.  True sonar devices send out sound waves, as we’ll discuss later.

Acoustic detection tends to shine in situations where the plumbing is pressurized and the leak is actively flowing, such as supply lines in walls, under slabs, and in hard-to-access areas where you want to avoid exploratory demolition. It’s also useful when a homeowner hears faint running water with fixtures off or notices a sudden pressure change that suggests an active leak.  However, it may struggle when there’s too much competing noise (busy households, HVAC vibration, nearby traffic), when the leak is extremely small, or when pipe materials and surrounding conditions dampen sound. In practice, this is why pros often confirm with a second method rather than relying on sound alone. (Inside Acoustic vs Thermal vs Electronic Leak Detection: When Each Method Shines)

As accurate as the demonstration videos seem, using a thermal camera could help you “double-check” before demolishing to uncover and repair the leak.  A hot water pipe in a slab or behind a wall should make a uniform heat signature all along the pipe, up until the leak, where the temperature field should expand as the hot water spreads outside the confines of the pipe.  If the water temperature is the same temperature as its surroundings, however, like cold water in a cold slab, this method might not be as helpful.

There are three other common methods of leak detection, but these are not generally used for scanning residential water pipes:

• Ultrasonic leak detection is used in pressurized gas systems, like the refrigerant system of your HVAC.  It detects high-frequency sound produced by a pressurized gas escaping from a vessel to identify a leak.  In the above article, electronic leak detection is more useful

• Electronic leak detection (ELD) pinpoints breaches in flat or low-slope roofing systems by tracing the flow of an electric current across the moistened membrane surface. Technicians use probes to detect current flow, precisely locating even pinhole leaks. (Electronic Leak Detection Services)

• Sonar leak detection is used in pipes, sewer drains, tanks and pools; the probe is underwater and it sends high-frequency sound waves into the pool. These sound waves travel through the water and bounce back when they encounter a surface or obstruction.  By measuring the time it takes for the sound waves to return, the equipment can calculate the distance to the source of the leak. (Sonar Leak Detection Equipment: The Precision Solution)

Since learning to accurately use all of these technologies takes time and practice, it’s probably best to hire a professional for a one-time leak, rather than buying the equipment yourself.   It may save you a lot of “patching” from unnecessary demolition, or even damaging perfectly good pipe in the process.

Photo by Ali Zargar on Unsplash