5 signs you have a slab leak — and what to do BEFORE you call a plumber

If you live in a slab-foundation home in Austin (especially anywhere in the hill country — Westlake, Lake Travis, Bee Cave), slab leaks are something to know about. The good news: modern detection and trenchless repair mean a slab leak is no longer a five-figure floor-destroying nightmare — IF you catch it early.

The 5 signs to watch for

1. Unexplained spike in your water bill

This is the cleanest signal. Check your last 6 months of water bills. A 30%+ increase with no change in habits (no new family member, no extended visitors, no leaks you've fixed) is the #1 reason we get called for slab leaks. Even a small slab leak loses 150+ gallons per day.

2. Warm or hot spots on the floor

Hot-water side slab leaks heat the slab above them. Walk barefoot in summer with the AC off — if a section of tile or hardwood is noticeably warmer than the surrounding area, that's a flag. (Cold-water leaks don't show this, but they're rarer.)

3. The sound of running water when nothing's on

Turn off every fixture in your house. Stand in a hallway and listen. If you hear water running, you have a leak somewhere — and if it's not visible at any fixture, it's almost certainly in the slab or an outdoor line.

4. Mildew smell or damp carpet without an explanation

Slab leaks wick moisture up through the slab into baseboards, drywall, and flooring. If you have a persistent damp smell in a specific room (or carpet that won't dry after a normal cleaning), look at the slab.

5. Cracks in walls/floors that weren't there last year

Long-running slab leaks soften and erode the soil under the foundation. The slab settles unevenly. You see hairline cracks in drywall, doors that suddenly don't close right, or tile that pops loose.

The three things to do BEFORE you call a plumber

1. Read your water meter twice, 30 minutes apart, with EVERYTHING off. If the meter advanced, you have an active leak. This proves there's a problem before you spend money on detection.
2. Photograph any wall cracks or warm spots. Date-stamped phone photos are useful — if it's a slab leak, your homeowner's insurance may cover the access (cutting the slab) and repair, but only if you document.
3. Call your insurance company first to ask about the slab-leak policy on your house. Most policies cover "sudden and accidental" water damage, not slow leaks — but the language varies. Ask before you have an estimate, not after.

What detection actually looks like

We use acoustic + thermal imaging. Acoustic = a sensitive microphone-on-a-pole that hears the leak through the slab. Thermal = an IR camera that picks up the warm spot from a hot-water leak. Combined, we locate the leak within 6 inches before any concrete gets touched.

From there, two options: repair in place (we cut a small section of slab, fix the pipe, patch back) or re-route through the attic / wall cavity to bypass the slab leak entirely. Re-route is usually cheaper and faster on older copper systems where one leak likely means more are coming.

The single biggest cost difference in slab leak repair is whether you caught it at month 1 or month 18.

If any of the 5 signs match what you're seeing, give us a call. Detection is $295 and waived if you book the repair — so worst case, you know.