How Leak Detection Works

1. Meter and isolation tests

With all fixtures off, a moving meter means water is escaping. Isolating zones shows whether the leak is on the supply line, inside the house, or in irrigation.

2. Pressure testing

Holding pressure on a section of pipe shows whether it is sealed. This is how pool lines and slab lines are separated from the rest of the system.

3. Acoustic listening

Ground and surface microphones pick up the sound of leaking water so we can trace it to its loudest point.

4. Thermal imaging and moisture mapping

Infrared cameras and moisture meters show where walls, ceilings and floors are wetter or at different temperatures than their surroundings.

5. Camera inspection

A camera run through drain and sewer lines shows cracks, root intrusion and breaks without digging.

Match the method to your situation on our services page.

Tracer gas detection

When a line can't be pressurized with water for testing, we fill it with a harmless tracer gas. A mix that rises through soil and concrete. A sensitive sniffer above the surface follows the gas to the exact leak point. It is especially good for finding small leaks under slabs and driveways where acoustic listening alone isn't conclusive.

Correlator loggers

Two sensors clamp onto the pipe at different access points. Hose bibs, meters, valves. They listen for the leak's sound and compare when the sound reaches each sensor. The time difference places the leak at a measured distance along the pipe. Good for long service lines between the meter and the house.

Ground-penetrating radar (GPR)

GPR sends radar pulses into the ground and reads the reflections. It maps buried pipes and voids so we know where to test. Useful when there are no plans of the underground plumbing, which is common in older Citrus Heights homes.

Sewer camera inspection

A camera on a reel travels the sewer line and shows cracks, offsets, root intrusion and bellies on a monitor. It tells us exactly where the problem is and how bad it is before any digging is discussed.

Other methods in the kit

Some jobs need a different tool. Tracer gas leak detection uses a hydrogen tracer gas test to find a slow leak that makes no sound: we fill the line with a light gas mix and a sniffer picks up where it escapes. Ultrasound and a sonic listening device help on low-flow leaks that a ground microphone misses. An electromagnetic locator and utility locating gear trace the line route before we mark anything, and a dual frequency locator can tell a water line apart from other buried lines. For sewer lines, video pipe inspection and smoke testing show breaks and bad joints without digging. Line tracing marks the pipe path across the yard so the dig, if one is needed, lands in the right spot. A pressure isolation test confirms which section loses pressure, and ground penetrating radar maps what sits under the slab. All of these are nondestructive testing methods. The pipe and the floor stay intact while we work. The approach stays diagnostic-first: test, locate, then report. That is what non-invasive leak detection means here, and a good leak locator earns the name by pinpointing first. In short, this is how to find a water leak without tearing up the house.

Choosing the right tool

No single instrument wins every job. The method follows the evidence: meter behavior and pressure tests tell us which system is leaking, then acoustic, thermal, gas or camera work pins the exact point. See the homeowner version in our guide: how plumbers find hidden water leaks.

Frequently asked questions

Last updated: October 25, 2026.