How Does a Plumber Find a Water Leak Underground?

Not all plumbing problems announce themselves with a puddle. Sometimes, the only clue is a spike in your water bill. Other times, it’s damp flooring with no apparent cause, or worse, the subtle sound of running water when everything is turned off. When you can’t see the issue but something’s off, it’s time to look below the surface. In many cases, you’re dealing with an under-slab leak, and solving it takes more than a wrench and good intentions.

Finding a leak under a concrete slab is one of the more complex tasks in plumbing. At FitzGerald & Sons Plumbing Company, we’ve built a reputation for doing it with care, strategy, and the right tools for the job. Here’s how we do it.

Step One: Start With the Clues

Before any equipment comes out, we listen to you and your home. Have you noticed hot spots on the floor? Do you hear water moving when it shouldn’t be? We take these red flags seriously from the start.

Step Two: Listen Beneath the Slab

We use specialized acoustic gear that can detect the sound of leaking water through concrete. This tech gives us a starting point, helping us narrow the area without unnecessary digging. That’s where under-slab leak detection begins: quiet, careful, and incredibly effective.

Step Three: Isolate the Problem

Next, we section off parts of your plumbing system and perform pressure tests. This helps us locate where pressure drops, meaning water escapes somewhere it shouldn’t be.

Step Four: Pinpoint the Leak

Once zeroed in, we confirm the exact location with tools like thermal imaging or tracer gas. These tools help us work efficiently while protecting your flooring and foundation as much as possible.

Step Five: Make the Repair Count

When it’s time for under-slab leak repair, we tailor the fix to your home. That might mean cutting into the slab or rerouting plumbing around the issue. We do what’s right for the long term, not just what’s easy at the moment.

An underground leak is never convenient, but with the right team, it doesn’t have to turn into a major disaster. If you’re seeing the signs or simply suspect a leak, let FitzGerald & Sons handle it with experience, clarity, and care. We’ll find the source and make it right the first time.