Homeowner guide
Slab leaks: the signs and what to do next
A leak under the foundation can run for weeks before it shows. Here is what to look for.
Start here
What a slab leak is
Many Austin-area homes are built on a concrete slab, with water lines running in or under it. When one of those lines leaks, the water goes into the soil and the slab, and up into the flooring above.
Central Texas clay soils swell when wet and shrink when dry. That movement puts stress on foundations and the pipes that run through them.
Signs
What to look for
- A warm or hot spot on the floor (a leak on a hot water line)
- The sound of running water when every fixture is off
- A water bill that goes up without a reason
- Damp carpet, or wood or laminate flooring that cups, swells or lifts
- Cracks in tile or in the slab that are new or growing
- A musty smell near the floor
- The water heater running more than usual
A simple check
The water meter test
- Turn off every faucet, appliance and irrigation zone in and around the house.
- Find your water meter, usually in a box near the street, and look at the leak indicator (a small dial or triangle).
- If it is moving with everything off, water is flowing somewhere.
- To narrow it down, close the main shutoff at the house and check the meter again. If it stops, the leak is likely inside the house. If it keeps moving, it may be in the line between the meter and the house.
This does not tell you exactly where the leak is. Locating a leak under a slab takes leak detection equipment.
After it is found
Two jobs: the leak and the water damage
The leak has to be located and repaired. That is one job. The water that has already soaked into flooring, the bottom of walls and cabinets is a second job, and it is the one that gets missed.
That is where we come in. We measure how far the moisture spread, remove flooring or materials that cannot be dried in place, dry the structure and rebuild: flooring, baseboards, cabinets and finishes. If the leak has been running a long time, document it with photos and check your policy, because many policies treat long-term leaks differently from sudden ones. Our insurance claim assistance page explains what we provide.
Call (512) 838-4236, someone answers, day or night.