Short answer
Common slab leak signs are a warm spot on a tile or concrete floor, the sound of running water with everything off, a water meter that keeps moving, a water heater that runs constantly, and cracked or damp flooring. Plumbers confirm a slab leak by isolating and pressure-testing lines, then pinpoint it with acoustic and thermal equipment.
The warning signs
Many Southern California homes sit on concrete slabs with copper water lines underneath. Leaks there can run for weeks unseen.
- Warm or hot spots on the floor (hot-water line)
- Sound of running water with all fixtures off
- Water meter moving with everything off
- Water heater running more than usual
- Cracks in tile, damp carpet or swelling wood floors
- Unexplained jump in the water bill
How to do a meter test
Turn off every faucet, appliance and the irrigation system. Look at the meter's leak indicator, usually a small triangle or dial. If it moves, water is going somewhere. Close the house shutoff: if the meter stops, the leak is inside the house; if it keeps moving, the leak may be on the service line in the yard.
Not sure it is safe to keep running? A local technician can check it today.
Call NowHow plumbers pinpoint it
Hot and cold lines are isolated and pressure-tested to confirm which one leaks. Acoustic equipment picks up the sound of water escaping under concrete, and thermal imaging shows the warm trail of a hot-water leak. The goal is to open one small area, not the whole floor.
Spot repair or reroute?
A spot repair breaks the slab at the leak, fixes the pipe and patches the concrete. A reroute abandons the leaking section and runs new pipe through walls and attic. Older copper with one failure often has more coming, which can make a reroute the better long-term choice, especially under expensive flooring.
Related questions
Is a slab leak an emergency?
Water surfacing through the floor or a rapidly rising meter is urgent. A slow leak still needs prompt repair because water can wash soil from under the slab and damage flooring.
How long does slab leak detection take?
Often a few hours, depending on how many lines must be tested and how noisy the surroundings are.
Does insurance pay for slab leaks?
Policies vary. Some cover access and resulting damage but not the pipe repair. Check with your insurer.
Services that fix this
Slab Leak Detection & Repair
Leaks in water lines under concrete floors, found and repaired by spot repair or reroute.
Slab leak repair in ParamountLeak Detection
Find hidden leaks in walls, ceilings, slabs and yards without tearing the house apart.
Leak detection in ParamountThis guide is general information for homeowners, not a diagnosis of your system. For anything involving gas, carbon monoxide, electricity or active leaks, stop and call a qualified professional.
