Leak Detection & Slab Leak Repair

The Leak You Can't See Is the One Doing the Most Damage

A dripping faucet is annoying. A leak inside a wall, under a slab, or buried in a yard is something else entirely, it can run for weeks or months before anyone notices, quietly driving up water bills and causing damage that's far more expensive to fix than the leak itself. By the time water starts showing up somewhere visible, the damage is often already done.


Commercial properties and multi-family communities are especially exposed here, since a hidden leak affecting shared or underground lines can go unnoticed across an entire building before it's caught. Hospitals and schools need leaks addressed quickly given the operational and safety stakes. And homeowners are often the ones who first notice something's wrong through a water bill that doesn't match their usage, long before they can see or hear the actual leak.


West Coast Hydro-Jet has located and repaired hidden leaks and slab leaks throughout Los Angeles, Orange County, the Inland Empire and San Diego for more than 34 years, using our own trained technicians and the equipment needed to find a leak without guesswork.

Signs of a Leak You Can't See

Hidden leaks rarely announce themselves directly. Watch for:

  • An unexplained spike in your water bill, especially without a corresponding change in usage
  • The sound of running water when no fixtures are in use
  • Damp spots, warping, or discoloration on floors, walls, or ceilings
  • A musty smell or unexplained mold growth, often a sign moisture has been present for a while
  • Low water pressure, which can indicate water is escaping the system somewhere along the line
  • Cracks in flooring or foundation shifting, in more serious or long-running cases
  • A water meter that keeps moving even when everything in the building is turned off



Not All Leaks Behave the Same Way

A visible leak, like a dripping fixture or a leaking pipe under a sink, is usually straightforward: we can see it, diagnose it, and repair it directly. Hidden leaks are a different challenge entirely. A slab leak occurs in a water line running beneath a concrete foundation, completely out of sight and often not directly accessible without locating the exact source first.


For slab leak repair, our technicians use specialized detection methods, including acoustic listening equipment and pressure testing, to pinpoint the leak's location without unnecessary digging or demolition. That precision matters, since guessing wrong on a slab leak can mean tearing into the wrong section of flooring before finding the actual source.

Why Pipes Start Leaking


Leaks don't usually happen for no reason. Understanding the cause helps determine both the right repair and whether it's an isolated issue or a sign of a bigger problem developing elsewhere in the system.

  • Aging or corroded pipes, particularly older galvanized steel or certain copper lines that break down from the inside over decades of use
  • Ground shifting and settling, common throughout Southern California, which can stress and crack pipes, especially slab lines, over time
  • High water pressure, which puts ongoing stress on pipes, joints, and fittings and can eventually cause a failure
  • Tree root intrusion, where roots seeking moisture work into small cracks or joints and widen them over time
  • Poor original installation or substandard materials, which can fail years before a properly installed system would
  • Temperature fluctuations, which cause pipes to expand and contract, gradually weakening joints and connections


If we find one leak caused by a systemic issue like high water pressure or aging pipe material, we'll flag that during the repair, since it often means more leaks are likely elsewhere.


The Cost of Waiting

A small leak rarely stays small. Left alone, a slow leak inside a wall can lead to warped flooring, damaged drywall, and mold growth that costs far more to remediate than the original leak would have cost to fix. A slab leak left unaddressed can undermine a foundation over time, turning a targeted slab leak repair into a major structural project. And every leak that goes undetected keeps adding to a water bill, month after month.


For commercial properties, an undetected leak can also mean unexplained utility costs that are hard to budget for and harder to explain after the fact. For multi-family communities, a leak in a shared line can affect several units before anyone identifies the source.

From Locating the Leak to Fixing It

Finding a hidden leak takes the right equipment and the experience to interpret what it's telling you. Our technicians can locate and repair from a single dripping valve to a slab leak buried under a commercial building's foundation.


Once we've pinpointed the leak's exact location, the repair itself depends on where it is and what caused it. Many leaks, including many slab leaks, can be fixed with a targeted spot repair, accessing just the section of pipe that's failed rather than replacing an entire line. In cases involving widespread corrosion or aging pipe material throughout a property, a broader repipe may be the more practical long-term solution.


We'll walk you through the options for your specific situation, with a clear, upfront price before any work begins, so you're never surprised by scope creep once a wall or floor is already open.

Frequently Asked Questions About Leak Detection


Mechanic in blue coveralls and cap holding a wrench, standing on a white background
  • How can I tell if I have a hidden leak?

    Common signs include an unexplained increase in your water bill, the sound of running water when nothing is in use, damp spots or discoloration on floors or walls, and a water meter that continues moving when all fixtures are off.

  • What is a slab leak?

    A slab leak occurs in a water line running underneath a concrete foundation. Because it's hidden beneath the slab, slab leak repair typically requires specialized detection equipment to locate the leak before it can be fixed.

  • How do you find a leak without digging up my whole property?

    We use acoustic listening equipment and pressure testing to pinpoint a leak's exact location before any digging or repair work begins.

  • What usually causes a hidden leak?

    Common causes include aging or corroded pipes, ground shifting, high water pressure, tree root intrusion, and poor original installation.

  • Will I need to repipe my whole property because of one leak?

    Not necessarily. Many leaks can be fixed with a targeted spot repair. A broader repipe is usually only recommended when the underlying pipe material is old enough that more leaks are likely to follow.

  • Is leak detection included with the repair, or is it a separate service?

    Detection and repair are typically handled together as one process, so once we locate the leak, we can move directly into fixing it.

Stop Guessing Where the Water's Going


Availaable 24 hours a day, 7 days a week including holidays, contact us at 800-750-4426 to schedule service.