A slab leak — a water line leaking under your concrete foundation — is one of the sneakiest and most damaging plumbing problems a Cibolo homeowner can face. On the expansive clay soil common here, they're also more frequent than most people realize. Knowing the warning signs lets you catch one before it does real damage.
1. A warm spot on the floor
This is the classic tell for a hot-water slab leak. If one area of your floor is noticeably warm underfoot — especially on tile — hot water may be escaping from a line beneath the slab. Cold-water leaks won't give this sign, but the others below apply to both.
2. A water bill that jumped for no reason
If your usage didn't change but your bill spiked, water is going somewhere you're not using it. A slab leak runs continuously, so it shows up on the bill. Check your meter with everything off — if it's still moving, you have a leak somewhere.
3. The sound of running water
If you hear water running when every fixture is off, a hidden leak — possibly under the slab — is a strong suspect. It's easiest to notice at night when the house is quiet.
4. Cracked or heaving flooring
Water escaping under the slab saturates the soil and can cause flooring to crack, buckle, or heave. Combined with clay soil movement, this is a red flag worth investigating.
5. Low pressure and a musty smell
A slab leak can reduce water pressure as it bleeds off supply, and the trapped moisture can produce a musty smell or even mold along baseboards. Damp carpet with no obvious source is another sign.
What to do if you suspect one
Don't let anyone break your slab to 'go look.' Professional leak detection uses pressure testing, acoustic sensors, and infrared to pinpoint the leak first. Then our slab leak repair team gives you options — a targeted spot repair, or rerouting the line to avoid opening concrete entirely.
Common across the clay belt
Homeowners in Cibolo and neighboring Selma sit on the same expansive clay and see the same slab-leak pattern. Catching it early — at the warm-spot or high-bill stage — saves your floors, your foundation, and your budget. Call (831) 290-4327 the moment you suspect one.
Our Confirm-Before-You-Cut Process
The worst thing a plumber can do with a suspected slab leak is start breaking concrete to 'go look.' We confirm first. We isolate the hot and cold systems and pressure-test to prove there's a slab leak and which line is losing water, then use acoustic sensors and, where useful, infrared to mark the exact spot — so any opening is small and deliberate.
Then we give you options, not a jackhammer. Depending on the leak's location and your pipe's age, rerouting the line overhead or through walls can bypass the slab entirely and often costs less than opening and restoring concrete. A spot repair fixes just the failed point. You see the findings and choose — nothing gets opened on a guess.
Frequently Asked Questions
Urgent enough to act on promptly. It runs continuously, wasting water and inflating your bill, and the escaping water can saturate soil under the foundation and damage flooring. It's not usually a same-hour emergency, but it shouldn't wait weeks — call as soon as you notice the signs.
No. A slab leak is a pressurized pipe losing water under concrete; it only gets worse as the opening erodes. The warm spot, high bill, or running-water sound won't resolve on its own — earlier detection just means a smaller, cheaper repair.
It can, over time. Water saturating expansive clay under the slab contributes to the soil movement that stresses foundations and cracks flooring. That's another reason to confirm and fix it promptly rather than watch and wait.
Cibolo Pro Plumbing
Licensed Texas plumbers (TX Master Plumber (TSBPE)) based in Cibolo, serving the Metrocom for 15+ years. Have a question about your home's plumbing? Call (831) 290-4327.
