Most homes in West and Central Texas sit on concrete slab foundations, with water and drain lines running underneath. When the soil under the slab shifts, those lines can crack. A slab leak can run for weeks before anyone notices, so knowing the early signs can save you a lot of money and mess.
Why slab leaks are so common in Texas
Much of Texas has expansive clay soil. It swells when it is wet and shrinks when it dries out. Long droughts followed by heavy rain, which is a familiar pattern from Midland to Waco, make the ground under a house move. That movement, plus age, corrosion, and water pressure, puts stress on the pipes under the slab.
8 warning signs of a slab leak
- Your water bill jumps without a change in how you use water.
- You hear running water when every faucet and appliance is off.
- Warm or hot spots on the floor, which can mean a hot water line is leaking under the slab.
- Damp carpet, warped wood, or loose tile with no obvious source.
- Mold or a musty smell near baseboards or under flooring.
- Low water pressure throughout the house.
- Your water heater runs constantly, because a hot water leak keeps pulling in cold water.
- New cracks in walls, floors, or the foundation itself.
How to check for a leak yourself
Turn off every faucet, the dishwasher, washing machine, ice maker, and irrigation. Then find your water meter (usually in a box near the street) and watch it for 15 to 30 minutes. If the meter moves or the leak indicator spins while nothing is running, water is going somewhere it should not.
This does not tell you where the leak is. Toilets and irrigation lines are common culprits too, so rule those out before you assume the worst.
How plumbers find and fix slab leaks
A licensed plumber with leak-detection equipment can usually pinpoint a slab leak without tearing up whole floors, using acoustic listening devices, pressure testing, and thermal imaging. Once they find it, the usual options are:
- Spot repair: cutting into the slab at the leak and repairing that section.
- Rerouting: abandoning the leaking line and running a new one through the walls or attic.
- Repiping: replacing the supply lines, often the better choice when an older home has had more than one leak.
Ask your plumber to explain why they recommend one option over another, and get the estimate in writing.
Will insurance cover it?
It depends on your policy. Many homeowners policies cover the water damage, and sometimes the cost to access the pipe, but not the repair of the pipe itself. Call your insurer before work begins and keep the plumber’s leak-detection report and photos.
Do not wait on it
A slab leak rarely fixes itself. The longer it runs, the higher the water bill and the bigger the risk of mold and foundation damage. If you see two or more of the signs above, call a licensed plumber and ask for leak detection.