Meyer's Plumbing — Service Guide
Slab Leak Detection & Repair
A guide to understanding slab leaks — what causes them, how they're detected, and the repair options available when a water line fails beneath a concrete foundation.
What Is a Slab Leak?
A slab leak is a leak in a water supply or drain line that runs beneath the concrete foundation of a home or building. In Texas and much of the South, homes are commonly built on slab foundations — a single poured concrete pad — with plumbing lines embedded in or running directly under the slab.
Because these pipes are inaccessible without breaking through concrete, slab leaks are among the more serious plumbing problems a homeowner can face. Left unaddressed, a slab leak can erode the soil beneath the foundation, cause structural settling, promote mold growth, and result in significant water damage to flooring and walls.
Signs You May Have a Slab Leak
Slab leaks are hidden by definition, but they produce recognizable symptoms. Catching them early limits the damage and the cost of repair.
Warm or Wet Spots on the Floor
A hot water line leak beneath the slab often produces warm spots on tile or hardwood floors. Wet spots, soft areas in carpet, or buckling flooring can indicate water migrating up through the slab.
Unexplained Water Bill Increases
A slab leak can run continuously without producing visible water. If your water bill has increased significantly without a change in usage, a hidden leak is a likely cause.
Sound of Running Water
Hearing water running when all fixtures are off — particularly near the floor or foundation — is a strong indicator of a pressurized supply line leak beneath the slab.
Drop in Water Pressure
A break in a supply line beneath the slab reduces the pressure available to the rest of the house. A noticeable and unexplained drop in pressure throughout the home warrants investigation.
Mold or Mildew Odor
Moisture migrating up through the slab creates conditions for mold growth in flooring, baseboards, and wall cavities. A persistent musty smell — especially near the floor — can indicate a long-running slab leak.
Foundation Cracks or Door Misalignment
Sustained water erosion beneath the slab can cause soil movement and foundation settling. Cracks in the slab, walls, or exterior, and doors or windows that no longer close properly, can be downstream effects of an unaddressed slab leak.
How Slab Leaks Are Detected
Locating a slab leak precisely before any concrete is broken is critical. Professional detection minimizes the access needed and reduces repair costs.
Pressure Testing
The plumber isolates sections of the plumbing system and pressurizes them to confirm which line is leaking and roughly where the pressure loss is occurring. This narrows the search before more precise locating begins.
Acoustic Leak Detection
Electronic listening equipment amplifies the sound of water escaping under pressure. By moving the sensor across the floor, the plumber can pinpoint the location of the leak based on where the sound is loudest.
Thermal Imaging
Infrared cameras detect temperature differences in the floor surface caused by a hot water line leak beneath the slab. The warm water creates a visible thermal signature that helps confirm and locate the leak.
Slab Leak Repair Options
Once the leak is located, there are several repair approaches. The right choice depends on the pipe material, the location of the leak, the age of the system, and the overall condition of the plumbing.
Spot Repair (Direct Access)
The most straightforward approach: the concrete is opened at the precise location of the leak, the damaged section of pipe is repaired or replaced, and the concrete is patched. It works well when the leak is isolated and the rest of the pipe is in good condition.
Pipe Rerouting
Rather than breaking through the slab, the leaking line is abandoned and a new line is run through the walls, attic, or other accessible areas. Rerouting avoids concrete work entirely and is often the preferred option when the existing under-slab pipe is old or in poor overall condition.
Tunneling
A tunnel is dug beneath the slab from outside the foundation to reach the leaking pipe without breaking through the interior floor. Tunneling preserves flooring and finishes and allows access to multiple points along the pipe run. It is a good option when the leak is in a location where rerouting isn't practical and floor preservation is a priority.
Common Questions About Slab Leaks
Think You Might Have a Slab Leak?
Meyer's Plumbing uses electronic detection equipment to locate slab leaks precisely before any concrete is touched. Call for a free assessment and a clear explanation of your repair options.