How slab leaks are found
Slab Leak Detection Services in Texas
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Finding a leak under concrete is a process of narrowing down. Each step rules something out until the leak can be marked on the floor. Call and we’ll connect you with a local Texas crew for slab leak detection.
We’ll connect you with a local detection crew.
The sequence in outline
- History and symptoms
- Meter check
- Isolating the lines
- Pressure testing
- Pinpointing the leak
- Confirming and marking
See slab leak detection for the service overview. This page explains each method.
History and symptoms
The technician asks what you noticed, where and when. Warm spots, sounds, bills and damp areas all give a starting point. Age of the home, pipe material and any past repairs shape what is likely.
Meter check
With everything off, a moving meter confirms water is escaping. Closing the main at the house tells the technician whether it is on the service line or the house side. See water meter leak check.
Describe the signs and we’ll take it from there.
Isolating the lines
The technician closes sections of the plumbing, such as the hot side, the cold side and individual branches, and watches for pressure loss. This narrows down which line is leaking, and whether the leak is above or below the floor.
Pressure testing
Gauges are connected to a section, and the pressure is watched over time. A drop shows loss. The technician does this, and homeowners should not attempt it.
Acoustic listening
Sensitive microphones and ground sensors pick up the sound of water escaping under pressure. The technician moves along the floor and listens for where the sound is strongest. It works well on metal pipe, and less well on plastic, and background noise can interfere.
A technician can explain each step.
Thermal imaging
An infrared camera shows temperature differences on the floor. A hot-water leak shows as a warm patch. It is most useful for hot lines, and less so for cold. See hot-water slab leaks.
Line locating
A locator traces the path and depth of a pipe so the technician knows where the line runs under the floor. Combined with listening and imaging, it lets the leak be marked precisely.
Camera inspection
For drain lines, a small camera is run through the pipe to see cracks and separations. See under-slab drain line leaks.
A local crew knows how homes in your area are usually plumbed.
Confirming and marking
Most technicians combine more than one method before marking the floor. They explain what they found, what is likely and what the options are before any opening is made. No method is perfect, and a technician should say how confident they are.
Describe the signs you have seen.
What can limit accuracy
Each locating method has conditions where it works best and conditions where it struggles. Knowing them explains why a technician may use more than one approach, and why the result is described as a likely location instead of a certain one.
- Floor coverings. Thick carpet, padding or stone can mute the heat a thermal camera would otherwise show.
- Background noise. Acoustic listening gives clearer results in a quiet house. Traffic, running appliances and nearby construction make a leak harder to hear.
- Pipe material. Plastic lines carry sound and heat differently from metal, so the method may change.
- Depth and soil. Water can travel along the pipe or through gravel before it surfaces, so the wet spot is not always above the break.
When results from two methods agree, confidence goes up. When they do not, the technician may repeat a pressure test on a smaller section of line before any opening is planned.
Preparing the house for testing
Most of the preparation is about quiet and access. Testing works best when no water is being used anywhere in the house, so plan to keep the dishwasher, washing machine, ice maker and irrigation off during the visit. If anyone in the household needs water at a set time, mention it when you book so the crew can plan around it.
The technician needs to reach the water meter, the main shutoff, the water heater and the fixtures in kitchens, baths and the laundry area. Clear a path to each. If the meter box is buried under mulch or grass, uncover the lid if you can do so easily.
Rugs over a warm or damp patch may need to be lifted so the floor can be scanned. Heavy furniture can usually stay in place, because acoustic and thermal equipment can work around it. Pets are best kept in one room, since the crew will move through most of the house.
How long the steps take
A meter check takes a few minutes. Isolating the hot and cold sides and pressure testing each one usually takes longer, because the line has to hold pressure for a set period before the reading means anything.
Acoustic listening and thermal imaging are where time varies most. A small house with a short run between the meter and the fixtures can be narrowed down fairly quickly. A larger house, a line that runs a long way under the slab, or background noise from traffic or appliances can stretch the search.
Camera work on drain lines adds time of its own, since the camera has to be fed through each section. Most locating visits fit within a few hours, and the technician can usually give a better estimate once the first tests show which line is losing water.
Understanding what you are told
At the end of a locating visit you should know three things: which line is leaking, roughly where the leak is, and how confident the technician is about that spot. Ask for each one directly if it is not offered.
The line matters because hot and cold supply lines, and drains, lead to different repair choices. The location matters because it decides how much floor would need to be opened for a direct repair, or whether bypassing the line makes more sense. Confidence matters because a mark on the floor is an estimate based on sound, heat and pipe position. A technician who has confirmed the spot with two methods can usually say so.
It also helps to ask whether the other lines were tested and held pressure. A clean result on the remaining lines is useful when you weigh a spot repair against a reroute or a repipe. If you want a second view before any repair, the marked location and readings are what another technician would need.
Asking for a second view
If you want another technician to look before any repair, ask the first crew to leave the marks on the floor and give you a summary of the readings. A second technician can then confirm the line and location rather than starting from nothing. Expect them to run at least a pressure test of their own. Two crews agreeing on the same spot is a good reason to go ahead with confidence.
Keep the summary with your other house records. If a leak appears on another line years later, it shows what was tested and what passed.
Slab leak location questions
No. The aim is to locate it first, so that any opening is small and in the right place.
They are good, not perfect. Combining methods improves confidence.
It depends on the house and the leak. Ask when you book.
The meter check is. Pressure testing and locating are for technicians.
Less well than on metal. The technician may use other methods.
Less reliably. It is best for hot-water lines.
Often, using many of the same methods.
The technician says so, and the search moves to other sources.
Listening needs quiet. Ask the household to keep noise down during it.
Book a leak search
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