Leak Detection in San Antonio, TX

Leak detection means locating a leak you can't see before anything is opened up — under a slab, inside a wall, beneath a driveway or in a ceiling void. To arrange leak detection in San Antonio, call (888) 862-0246.

Before you call, run the meter test below. It takes fifteen minutes, costs nothing, and tells you whether water is escaping on your side of the meter — which is the first thing anybody will want to know.

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San Antonio Plumber Pros is a referral service, not a plumbing contractor. Calls are connected to independent plumbing professionals who are solely responsible for the work they perform, including licensing, pricing, scheduling and workmanship. Availability varies by location and by time of day.

The meter test: do this first

Turn off every fixture and water-using appliance in the building. Include the ice maker, irrigation system, evaporative cooler and any water softener regeneration cycle.
Find the water meter, usually in a box near the street.
Look at the low-flow indicator — a small triangle, dial or star that spins on very low flow. Note the exact reading on the register.
Wait 30 to 60 minutes without using any water, then read again.

If the indicator moves or the reading changes, water is passing through the meter and you have a leak on your side of it. To narrow it further: close the main shutoff at the house and repeat. If the meter still moves, the leak is between the meter and the building — often a service line or irrigation. If it stops, the leak is inside.

Symptoms of a hidden leak

A water bill that rose without a change in usage.
The sound of running water when everything is off.
A warm or hot spot on a tile or wood floor — a classic indicator of a hot-side slab leak.
Hot water that never quite runs out of a particular area, or a water heater running more often than it should.
Damp carpet, a cupped or buckling floorboard, or tile grout that stays discoloured.
A musty or mildew smell with no visible source.
Cracks appearing in a slab, wall or floor tile, particularly alongside dampness.
Persistently low water pressure throughout the building.
A patch of lawn that stays green or soggy in dry weather.

Slab leaks and why San Antonio sees them

Most homes in the San Antonio area are built on concrete slabs, with supply and drain lines running through or beneath them. Two local factors make under-slab leaks a recurring issue.

The first is soil movement. Expansive clay in South Central Texas swells with moisture and contracts through drought cycles. The slab moves with it, and pipes fixed within or beneath the slab are stressed at bends and connections.

The second is water chemistry and pressure. Hard water and high static pressure both work against copper and older galvanised supply lines. Pinhole failures in under-slab copper are a well-known pattern, and a small pinhole under a slab can run for a long time before anything is visible indoors.

A leak on the hot side often shows itself first through a warm floor area or an unexplained rise in water heating. A cold-side leak may only appear as damp flooring, a raised bill, or nothing at all until the meter test finds it.

How professionals pinpoint a leak

Method	What it detects
Acoustic listening equipment	The sound of pressurised water escaping, amplified and traced across a floor or wall surface
Thermal imaging	Temperature differences at the surface, useful for hot-side leaks and for mapping the extent of moisture
Tracer gas	An inert gas introduced into an isolated line, detected where it surfaces — effective for small or intermittent leaks
Pressure isolation testing	Isolating sections to determine whether the hot side, cold side or drain system is losing water
Moisture meters	Moisture content in flooring, drywall and framing, to define the wet area
Drain line camera	Breaks and separations in waste lines, which don't hold pressure and so can't be leak-tested the same way

The point of all of this is to open the smallest possible area. Detection is what keeps a slab leak from becoming a demolition project.

Once a leak is located: the options

Spot repair. Break through the slab at the located point, repair the pipe, patch back. Direct, and appropriate for an isolated failure in otherwise sound pipe.
Reroute. Abandon the failed run and route a new line through the attic or walls, bypassing the slab entirely. Often chosen when access is difficult or when the same line has failed before.
Partial or full repipe. Where pipe of that age and material is failing repeatedly, replacing the system is sometimes more economical than a sequence of spot repairs.

If the same line has leaked more than once, ask about rerouting rather than repairing it again.

What to do while you wait

Leave the main shutoff off if the leak is significant, opening it only when you need water.
Don't open flooring, walls or a slab yourself — detection is far easier on undisturbed surfaces, and guessing wrong is expensive.
Photograph and date what you can see, and keep water bills showing the increase.
Get air moving across damp areas.
Check whether your water utility has a process for reviewing bills affected by a leak; many do, usually with documentation of the repair.
Contact your insurer early if damage is significant.

Need help with this in San Antonio?

Call to describe what you're seeing and find out what the next step should be.

Call (888) 862-0246

Frequently asked questions

How do I know if I have a hidden water leak?

Run the meter test. Shut off every fixture and appliance, note the meter reading and watch the low-flow indicator for 30 to 60 minutes. If it moves, water is escaping somewhere on your side of the meter.

What are the signs of a slab leak?

A warm spot on the floor, the sound of running water with everything off, damp or buckling flooring, an unexplained bill increase, a musty smell, or a water heater cycling more than usual. Not all slab leaks produce visible damage early on.

Can a leak be found without breaking the floor?

Yes — that is the point of detection. Acoustic equipment, thermal imaging, tracer gas and pressure isolation are used to pinpoint the location first, so that only a small area needs to be opened for the repair.

My water bill doubled but I can't see any leak. What now?

Start with the meter test, then check irrigation and any leaking toilet flappers, which are a very common silent cause. If the meter keeps moving with the house main closed, the leak is on the service line between meter and building.

Is a slab leak an emergency?

Not usually in the sense of needing someone at 2am, but it should not be left. Water under a slab continues to saturate soil, can affect the foundation, and keeps adding to your bill. Schedule detection promptly rather than waiting for visible damage.

Related plumbing services

Pipe Repair

Pinhole leaks, corroded supply lines, freeze splits, pressure problems and repipe decisions.

Plumber

General residential and commercial plumbing help — repairs, fixtures, valves, water pressure and diagnostics.

Emergency Plumber

Burst pipes, major leaks, sewer backups and no-water situations — plus what to do in the first five minutes.

Sewer Line Repair

Recurring main line backups, root intrusion, bellied or collapsed laterals and cast iron failure.

Where this service is available

San Antonio and surrounding communities, with coverage extending up to roughly 200 miles where participating professionals are available.

Full service area → · Contact details →

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Call (888) 862-0246. Calls are accepted around the clock, and availability depends on your location and the time.

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