Signs of a Hidden Water Leak
The leaks that cost the most are the ones you never see. Here is how to catch one before it finds your foundation.
35 years of licensed plumbing experience in the San Antonio area — 33 of them as a licensed Master Plumber and Responsible Master Plumber (RMP).
The Water Bill Is Usually the First Witness
An unexplained jump in the water bill, with no change in how the household uses water, is the single most reliable early sign of a hidden leak.
A simple check: shut off every fixture in the house, then watch the meter. If it is still moving, water is going somewhere it should not be.
What a Hidden Leak Feels Like
- A warm spot on the floor — often a hot-water line under the slab.
- The sound of running water when everything is off.
- Damp flooring, buckling, or a persistent musty or mildew smell.
- Water pressure that has quietly dropped.
- A soggy patch or unusually green strip in the yard.
- Cracks appearing in flooring or walls as soil beneath moves.
Why San Antonio Homes Are Vulnerable
Most homes here sit on slab-on-grade foundations, and the soil in this region moves with heat and drought. Supply lines under a slab are not accessible, and a small leak can run for a long time before it announces itself.
That is what makes it expensive: not the pipe, but everything the water reaches first.
Finding It Without Destroying the House
Leak detection uses testing and locating equipment to narrow down where the leak actually is before anyone opens concrete. That is the entire point — opening floors based on a guess is how homeowners end up with several holes and no answer.
Do Not Wait It Out
A hidden leak does not resolve itself, and the damage compounds — flooring, framing, and eventually the foundation.
If your meter is moving with everything shut off, call someone today.
Meter Moving With Everything Off?
Call us. We will find it before it finds your foundation.