How do you find the source of slab water leak?

Leak location begins by listening for and finding the loudest two points in the house, called a “points test.” Once that point is identified, a frequency transmitter is attached to the water lines. This produces a specific frequency that another locator device senses and detects. The readings allow us to create a “blue tape map” of the water lines on the floors.

From there, we use acoustic leak detection equipment to listen through the slab. The best way to describe this is an amplified stethoscope. We have some controls to adjust sensitivities and a measurement meter that allows us to gauge the loudest spots. The accuracy is largely based on the operators’ skills and experience but also on how directly we can get our devices over the buried water line.

If the leak happens to be located inside a concrete beam and/or spraying in a different direction, it can be harder to pinpoint. Many factors can interfere with getting an exact location: the size of the leak, the volume of water, the flooring type, cabinets, walls, and fixtures (tubs and showers). Our goal is to be exact, but as long as we are within three feet, we can make it work.

Earl’s Plumbing uses the same leak detection equipment and processes as a well-known nationwide franchise that specializes in leak location. In our early years, we used that franchise to do our leak locations. But it took 3 weeks to get on their schedule, which was not ideal for our customers.

So, we watched and learned their techniques, asked a lot of questions, and purchased identical equipment with manufacturer training. It is a difficult task and skill to master, but we have invested thousands of dollars and countless hours perfecting the craft.

We will occasionally use other devices and methods to pinpoint the location as well. The most common are:

• Compressed nitrogen: which produces a different sound than spraying water.
• Infrared thermometers: used to get temperature readings and differences.
• FLIR thermal imaging: used to see heat & cold differences behind structures.

Occasionally there is a second smaller leak in the plumbing system that doesn’t present itself until the first leak is repaired. This is very rare—so rare that it’s only happened a handful of times since 2020. Still, the initial repair quotes will always have some language that allows for additional repair steps and pricing flexibility.