What Is a Slab Leak and How Do You Know If You Have One?

For homeowners in Lafayette, Broussard, and across Acadiana, slab leaks are more common than most people realize. Older pipe materials, Louisiana's shifting clay soil, and our humid climate create the exact conditions that cause underground pipes to corrode and fail,  often with very little warning.

In this post, we'll cover what causes a slab leak, the warning signs to watch for in your home, how professionals find and fix them, and what it typically costs to repair one in the Lafayette area.

What Causes a Slab Leak?

Slab leaks are most often caused by a combination of aging pipes, soil movement, and corrosion, and Acadiana homes tend to check all three boxes.

Here's what's actually happening beneath your foundation:

What Are The Warning Signs of a Slab Leak?

The most common signs of a slab leak are warm spots on the floor, the sound of running water with everything shut off, an unexplained rise in your water bill, and cracks appearing in flooring or baseboards.

Most homeowners don't connect these dots until the signs stack up, which is why knowing what to look for matters.

Signs to watch for in your home:

• Warm or hot spots on the floor — especially on tile, hardwood, or concrete with no visible heat source nearby. This is one of the most reliable indicators of a hot water line leak beneath the slab.

• The sound of running water when everything is off — most noticeable at night in a quiet house. If you can hear water moving but nothing is running, take it seriously.

• A water bill that keeps climbing — without any change in your household's habits. If you've already ruled out a running toilet or dripping faucets and the bill is still rising, the leak may be underground.

• Cracks in flooring, baseboards, or drywall — caused by moisture swelling the materials from below. These often appear near the floor and get dismissed as normal settling.

• A musty smell or mold at floor level — water seeping up through or around the slab creates ideal conditions for mold growth, often before any visible moisture appears.

• A sudden drop in water pressure throughout the house — if pressure dropped noticeably and nothing else changed, a pressurized supply line leak beneath the slab may be the cause.

• Damp carpet or unexplained wet spots — particularly along walls or in the center of rooms with no spill to explain them.

None of these signs is definitive on its own, but two or more together, especially if they appeared gradually over the same period, are a strong indicator that something is happening below your foundation.

Can You Confirm a Slab Leak Yourself?

There is one diagnostic a homeowner can run themselves that takes about 20 minutes and gives you a clear yes or no on whether you have an active leak somewhere on the property:

1. Turn off every water source in the house - dishwasher, ice maker, washing machine, all faucets.
2. Find your water meter, usually at the curb in a small covered box near the street.
3. Note the exact reading, or watch the small triangle or dial indicator on the face of the meter.
4. Wait 20 minutes without using any water.
5. Check the meter again. If the reading changed or the dial moved, you have an active leak.

That test tells you a leak exists. What it cannot tell you is where the leak is, whether it's above or below the slab, how serious it is, or what it will take to fix it. That's where the diagnostic ends for a homeowner and where a professional takes over.

Locating a slab leak requires specialist equipment and trained experience. Acadiana Rooter uses acoustic leak detection,  sensors that listen for the distinctive sound signature of pressurized water escaping through a pipe buried in concrete. Combined with electronic amplification, pressure testing, and thermal imaging cameras that detect temperature changes at the slab surface, a trained plumber can pinpoint the source without tearing up your floor on a guess.

How is a Slab Leak Repaired?

A slab leak can be fixed in one of three ways:  a targeted spot repair, a pipe re-route, or trenchless pipe lining,  and which approach is right depends on the location of the leak, the age of your pipes, and what material they're made from.

Spot Repair

If the pipe is otherwise in good condition and the leak is isolated, a targeted jackhammer access point is cut into the slab above the leak, the damaged section is repaired or replaced, and the concrete is patched. It's the most straightforward option when the rest of the pipe system is sound.

Pipe Re-route

If the damaged section is in a difficult location — under a load-bearing wall, beneath tile that can't be disturbed, or in a spot that makes access cost-prohibitive — the pipe can be rerouted through the walls or attic, bypassing the slab entirely. This avoids excavation and is often the right call for specific sections of older systems.

NuFlow Pipe Lining

For homes with aging pipe systems throughout the slab, trenchless pipe lining is often the most cost-effective long-term solution. Rather than digging up and replacing individual sections, a flexible epoxy-coated liner is inserted into the existing pipe and cured in place, forming a seamless new pipe inside the old one, without excavation.

If your pipes are corroding in one spot, they're likely corroding elsewhere too. Lining the system addresses the root problem rather than waiting for the next failure.

What Should You Do if You Think You Have a Slab Leak?

If something in your home has been feeling off,  floors that are warmer than they should be, a water bill that won't stop climbing, a sound you can't place, trust that instinct and get it looked at. Slab leaks don't resolve on their own. Every day they run, they do more damage to the structure of your home and more damage to your wallet.

The good news is that a proper inspection gives you answers fast. You don't have to live with the uncertainty.

Why homeowners across Acadiana call us first:

• Licensed Master Plumber with over 28 years of experience diagnosing and repairing plumbing systems across South Louisiana
• NuFlow-certified pipe lining specialist, one of the only certified trenchless repair technicians in the Acadiana area
• Veteran-owned and operated, built on the same standards of discipline and precision Ben brought home from 15 years of military service
• We use professional acoustic leak detection, thermal imaging, and pressure testing — not guesswork- to locate slab leaks without unnecessary destruction to your home
• Local to Acadiana, which means we know exactly what Louisiana's soil, climate, and aging pipe systems do to homes like yours

At Acadiana Rooter Plumbing, we'd rather find a small leak today than help you deal with the fallout from a big one later. When you call us, you're talking to someone who has seen it all — and fixes it right the first time.

Frequently Asked Questions

At Acadiana Rooter Plumbing, we take pride in providing reliable, honest, and professional plumbing services across Lafayette, Broussard, Youngsville, and the surrounding Acadiana area. From drain cleaning and pipe repair to water heater installation and backflow testing, our licensed plumbers handle every job with precision and care. As a veteran-owned company, we’re committed to serving our community with integrity and craftsmanship you can trust.