Every house is a plumbing system wearing a building. Water enters under pressure, travels through walls and under floors, does its work, and leaves by gravity. When the system is intact, it is invisible and forgettable, which is exactly what you want from it. Leak detection is what happens when it is no longer intact and you need to know precisely where, without taking the building apart to look. It is the difference between a plumber cutting one hole and cutting five.
The definition, without the dictionary
Leak detection is the process of confirming that a plumbing system is losing water, determining which line is losing it, and locating the exact point of escape, all from the outside of the walls, floors, and ground that hide the pipe. The confirming part uses gauges. The locating part uses sensors and cameras. The whole thing uses experience, because instruments give readings and readings need interpreting.
Detection and repair are different skills. A leak detection specialist finds the leak and documents it. A plumber fixes it. We do both, which saves you a second company and a second appointment, and which deserves a word of caution: a company that profits from the repair has a reason to find a large problem. Our answer is to show you the evidence before the quote, so you can judge the finding for yourself.
Why it matters, and why it matters more here
The Environmental Protection Agency estimates that household leaks waste nearly 10,000 gallons per home per year across the country, and that one home in ten has a leak wasting 90 gallons or more every day. Those are national averages. Phoenix is not a national average. Our soil swells and shrinks with the seasons, our water is hard, our summers punish copper, and our houses sit on slabs that hide the pipes completely. A leak here is more likely, harder to see, and more expensive to ignore. It is also, in a valley that measures water in acre-feet, a small civic failure. Finding it fast is good sense and good citizenship.
~10,000 gal
per year wasted by the average leaking household
EPA WaterSense
1 in 10
homes has a leak wasting 90+ gallons a day
EPA WaterSense
1 hole
is what a good locate should cost you in demolition
Not five. Not a trench.
A plumber with a saw and a hunch is a search. A locator with instruments and a mark is an answer.
The methods, and what each one is for
Visual inspection
The oldest method and still the first. Stains, corrosion, warped flooring, and mineral crust all point somewhere. It is where a technician begins, never where one ends.
[Pressure testing](/pressure-testing-leak-detection)
Isolate a line, pressurize it, watch a gauge. A drop means a leak, and comparing lines tells us which one. It confirms and narrows the search before the searching begins.
[Acoustic detection](/acoustic-leak-detection)
Pressurized water escaping a pipe makes a sound. Ground microphones and correlators hear it through concrete, tile, and soil and find the peak. The backbone of slab and main line location.
[Thermal imaging](/thermal-imaging-leak-detection)
Infrared cameras show the temperature trail water leaves in floors, walls, and ceilings. A hot-water slab leak lights up the floor above it. A fast survey tool that points the others where to look.
Camera inspection
For drains and sewer lines, which flow by gravity and make little sound. A camera travels the pipe and a transmitter in its head lets us locate the defect from above.
Tracer gas and dye
Specialized confirmation methods for pools, spas, sealed systems, and situations where other signals are weak. Used when needed, not for show.
What a professional locate looks like
- 1
The interview
What you have seen, heard, felt, and paid. The water bill is evidence. So is a warm spot or a sound at night. A good technician listens before touching anything.
- 2
Confirmation
A meter check and pressure test establish that a leak exists and which system it is on. A surprising share of investigations end here with a running toilet.
- 3
Survey
Thermal imaging and a visual sweep narrow the field to a room, a wall, or a run of pipe.
- 4
Pinpoint
Acoustic listening, correlation, and pipe tracing find the spot. The mark goes on the floor, wall, or ground.
- 5
Report
Photos, a sketch, the line and material involved, and repair options in plain language. Handed to you before the truck leaves.
What to expect from a good one
A firm arrival window. Instruments, not a flashlight and a theory. Questions before answers. A mark you can see and a report you can forward. A repair quote that comes after the evidence, never before it, with no pressure to accept it. And honesty when the answer is “it was the sprinkler timer,” which happens, and which should cost you a service call and nothing more. If you want the short version of when to pick up the phone, read when to call a professional. If you want to check your own house first, read the signs of a leak.
Common questions about leak detection
How is leak detection different from plumbing?
Plumbing installs and repairs pipes. Leak detection finds where an existing pipe is failing, without opening things to look. Many plumbers do basic detection; specialists carry instruments and training that go further. We carry both: the instruments to find the leak and the plumbers to fix it.
Is leak detection destructive?
No. Modern methods are non-invasive. The only cutting happens during the repair, at the spot the locator marked.
How long does it take?
Most residential locates take one to three hours. Commercial sites and intermittent leaks take longer. A good technician tells you when a job is heading long.
Can I do it myself?
You can do the meter test and check the obvious places, and you should. Locating a leak under a slab or in a wall requires instruments and the experience to read them.