Signs of a slab leak — and what to do
A pipe leaking under the foundation is common in DFW clay. Know the signs.
By The T.A.P. Team · May 2024 · 6 min read
A slab leak is a water line leaking beneath your home's concrete foundation — and in North Texas, where expansive clay soil constantly shifts and stresses buried pipes, they're more common than homeowners expect. The signs can be subtle: a warm spot on the floor, an unexplained jump in your water bill, low pressure, or the sound of running water with everything off. Catching one early limits the damage.
- A warm or hot spot on the floor
- An unexplained spike in your water bill
- Low water pressure across the house
- The sound of running water with everything off
- New cracks in floors or walls, or damp/warped flooring
What a slab leak is
Most Texas homes sit on a concrete slab foundation, with water lines running through or beneath it. When one of those pipes develops a leak — from corrosion, abrasion, or soil movement — water escapes under the slab. Because it's hidden, a slab leak can run for a long time before it's obvious, which is why the early signs matter.
The warning signs
A warm spot on the floor often points to a leak in a hot-water line; a sudden high water bill or a meter that moves with everything off signals water escaping somewhere; and whole-house low water pressure can accompany it. You might also hear running water, notice damp or warped flooring, or see new cracks as the wet soil shifts.
Why North Texas is prone to them
DFW's expansive clay soil swells when wet and shrinks when dry, moving constantly with our wet springs and dry summers. That movement stresses foundations and the pipes running through them — the same soil behavior behind the region's foundation problems. It's why slab leaks (and the low pressure or cracks that hint at them) are a recurring North Texas issue.
What to do if you suspect one
Don't ignore it — a slab leak won't heal, and the longer it runs the more it damages flooring, the foundation, and your bill. Confirm the clue (check the meter with all water off), then call a plumber for electronic leak detection to pinpoint it without tearing up the whole floor. Repairs range from spot access to rerouting the line. See our plumbing services.
| Symptom | Likely cause | What to do |
|---|---|---|
| Warm spot on the floor | Hot-water line leak | Call for leak detection |
| Water bill spikes | Hidden leak under slab | Check the meter; call a pro |
| Whole-house low pressure | Possible slab leak | Isolate and inspect |
| Sound of running water | Active leak | Shut off; call a pro |
| New floor/wall cracks | Soil movement + moisture | Have it evaluated |
You can DIY
- Check the meter with all water off
- Note warm spots on the floor
- Track unexplained bill spikes
- Locate your main shutoff
- Photograph any new cracks
Call a pro
- Electronic slab-leak detection
- Any under-slab pipe repair or reroute
- Foundation-related concerns
- Confirming a leak's exact location
- Repairs after water damage
The worst way to fix a slab leak is to guess and jackhammer. Best practice is electronic leak detection to locate it precisely, then the least-invasive repair — spot access or rerouting that section of line. Finding it accurately first is what keeps a slab-leak repair from becoming a demolition project.
Slab leaks and North Texas clay
The same expansive clay that cracks DFW foundations also stresses the pipes beneath them, so slab leaks are a genuinely local problem across Frisco, McKinney, and Plano. We use leak detection to find them without tearing up your home. See our plumbing team.
The short version
- A slab leak is a water line leaking under your concrete foundation.
- North Texas clay soil shifts constantly, which makes slab leaks common here.
- Signs: a warm floor spot, a water-bill spike, low pressure, running-water sounds.
- Check your meter with all water off — if it moves, water is escaping.
- A slab leak won't heal; the longer it runs, the more damage it does.
- Have it pinpointed with electronic leak detection before any concrete is opened.
Slab leaks — frequently asked questions
Think you have a slab leak?
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