How do plumbers find a slab leak?

Most Texas leak-detection plumbers use a combination of acoustic listening (microphones on the floor), pressure isolation testing (cutting the system into segments and watching gauge drop), and thermal imaging (infrared cameras spot warm hot-water leak paths). Tracer gas (helium injection) is sometimes used for stubborn cases.

What does slab leak detection cost in Texas?

Detection alone runs $300–$900 in 2026 across major Texas metros. Detection plus repair (slab break + spot fix) typically runs $2,500–$5,000. A full reroute through the attic to bypass the slab section runs $1,800–$5,500.

Should I break the slab or reroute the line?

Reroute is usually preferred when: (1) the home has had multiple slab leaks (the rest of the line will fail soon), (2) the leak is under finished tile or hardwood that's expensive to repair, or (3) the line is old copper or galvanized that's already past life. Spot repair is fine when the leak is in an isolated, accessible location and the rest of the system is healthy.

Will homeowner insurance cover a slab leak in Texas?

Texas homeowner policies generally cover the water damage from a sudden slab leak (drying, flooring repair) but do NOT cover the leak repair itself. Some policies offer a 'service line' rider that covers the repair too. Check your policy before agreeing to a full reroute — it changes the math.

Plumbing · Texas slab homes · Updated April 2026

Slab leak in Texas? How detection works, what it costs, and when to reroute

If you live in a Texas slab home built after 1970, you have a non-trivial chance of a slab leak in your lifetime. Expansive clay soil moves with seasonal moisture, copper supply lines flex along with it, and after enough cycles, a fitting fails. Here's what actually happens next.

Signs you have a slab leak

Water bill jumped without an obvious explanation
Hot spots in the floor (hot-water side leaks heat the slab above)
Sound of running water with no fixture on
Damp carpet or warped flooring with no visible source
Hot water pressure noticeably weaker than cold
Mildew smell from baseboards or under cabinets

The fast confirm: turn off every fixture in the house, then watch the water meter dial at the curb. If it's still moving, you have a leak somewhere — and if no fixtures are on, that "somewhere" is in the supply line, often under the slab.

How detection actually works

1. Acoustic listening

A leak under pressure makes noise — a high-pitched hiss that travels through the slab. Specialized ground microphones can localize that sound to within a few feet. Works best for hot-water leaks (water flashes to vapor when it escapes, louder signature).

2. Pressure isolation

The plumber cuts the home's system into segments and pressure-tests each one. Whichever segment loses pressure has the leak. This narrows the search before acoustic localization, especially in big homes with a long supply run.

3. Thermal imaging

Infrared cameras show the warm path of a hot-water leak under the slab. Useful for confirmation more than primary detection — usually paired with acoustic.

4. Tracer gas

When acoustic fails (cold-water leak, very small flow, deep slab), the plumber bleeds the line and pumps helium gas through it. The gas escapes at the leak point and rises through cracks; a sniffer detects the helium at the surface. Slow but accurate when nothing else works.

Spot repair vs. full reroute

Once detected, you have two paths:

Slab break + spot repair

Plumber jackhammers a 2x2 ft section of slab
Cuts out and replaces the leaking section of pipe
Pours fresh concrete to seal
You restore flooring on top
Cost in 2026 Texas: $2,500–$5,000 plus flooring repair

Reroute (bypass the slab)

Plumber abandons the leaking line in place
Runs new PEX through the attic and down through walls to the same fixtures
No concrete cut, no flooring damage
Cost in 2026 Texas: $1,800–$5,500 depending on number of fixtures rerouted

When to choose which

Choose spot repair if: the home is younger than 15 years, this is the first leak, the leak is in a closet or garage where flooring repair is cheap, and the rest of the system is accessible if more leaks come up.

Choose reroute if: this is the second or third leak, the home is older than 25 years on copper supply, the leak is under tile or hardwood, or the slab break would land under cabinets where repair is structurally complex.

What to ask before approving the repair

Will you pull the permit? (Required in most Texas cities)
What flooring/drywall restoration is included?
Warranty on the repair joint vs. the rest of the line
For reroute: are you replacing all hot-water lines or just the failed one?

Prevent the next one

Install a whole-house pressure-reducing valve (PRV) and verify it's holding 60–70 PSI
Foundation watering during summer drought reduces clay shrinkage and the cyclical movement that flexes pipes
Flush the water heater annually — sediment-laden tanks fatigue supply line connections