Slab Leak Detection and Repair in Austin, TX

Think you have a slab leak? Do this right now: shut off your water at the main valve or the meter, snap a photo of the meter reading, and call Lantz Home Services at 512-710-1032. We have been finding and fixing hidden leaks under Central Texas homes since 1972. In most cases we can pinpoint a slab leak within one to two hours and repair it the same day, without tearing up your whole floor.

A slab leak is a leak in a water or sewer line running beneath the concrete slab your home sits on. It never gets better on its own. It washes out the soil supporting your foundation, feeds mold behind walls and under flooring, and quietly adds hundreds of dollars to your water bill. Caught early, most slab leaks are a one day repair. Ignored for months, they become a foundation problem that costs ten times as much.

The 10 Minute Slab Leak Check You Can Do Before You Call

Neither of us wants to schedule a leak call for a running toilet flapper. This simple meter test tells you in about ten minutes whether water is escaping somewhere on your property.

1. Turn off every fixture and appliance. No faucets, no ice maker, no washing machine or dishwasher mid cycle, irrigation off. Jiggle toilet handles so nothing is silently running.
2. Find your water meter. It is usually near the street at the front of your property under a concrete or plastic lid.
3. Watch the leak indicator. Most meters have a small triangle, star, or gear that spins with even a trickle of flow. If it is moving with everything off, water is leaving the system somewhere.
4. Narrow it down with the house shutoff. Close the shutoff valve where the line enters your home, often in the garage, at an exterior wall, or in a box near the foundation. If the indicator keeps spinning, the leak is in the yard line between the meter and the house. If it stops, the leak is inside the house, and if you also have any of the warning signs below, under the slab is the prime suspect.
5. Confirm with a 30 minute reading. Note the meter reading, use no water for 30 minutes, and check again. Any movement confirms a leak.

This test tells you that a leak exists, not where it is. Finding the exact spot under several inches of concrete takes electronic detection equipment, and precision is everything. Every foot of error in locating a slab leak means another foot of concrete opened up for nothing.

Warning Signs of a Slab Leak in Austin Homes

Slab leaks come in two varieties, and they announce themselves differently. Pressurized water lines leak constantly and show up fast. Sewer and drain lines only leak when water runs through them, so they can quietly saturate the soil under your home for years.

Signs of a water line slab leak

• Warm spots on the floor. Roughly 8 out of 10 slab leaks we find are on the hot water side, because hot water accelerates corrosion from the inside. A patch of warm tile in summer is a classic giveaway.
• The sound of running water when everything is off. Often loudest at night near the water heater or a bathroom wall.
• A water bill jump you cannot explain. A pinhole leak under pressure can lose thousands of gallons a month.
• A water heater that never stops running. A hot side leak drains the tank continuously.
• Damp carpet, cupped wood flooring, or loose tiles. Moisture migrating up through the slab.
• Drop in water pressure at multiple fixtures at once.
• Musty smells or mildew along baseboards with no visible source.

Signs of a sewer line slab leak

• Recurring drain backups or slow drains in the same part of the house. If a clog keeps coming back no matter how many times drain cleaning clears it, the line itself may be broken under the slab, and clearing the drain clog again only treats the symptom.
• Sewer or musty odors that come and go, strongest after heavy water use.
• A raised or domed section of floor. Saturated clay under the slab expands and can literally lift it. Plumbers call this a heave.
• Cracks in tile, drywall, or brick, and doors that suddenly stick. Signs the slab is moving on soil that a leak has softened or swollen.
• One suspiciously green patch of lawn against the foundation during a dry Austin summer.

Two or more of these together is a strong signal. Many of these symptoms get misdiagnosed as foundation problems first, and homeowners spend thousands on piers when the real culprit was a leak that kept moving the soil. Rule out the leak before you hire a foundation company.

Why Austin Homes Are Prone to Slab Leaks

Slab leaks are not random bad luck here. Central Texas geology and water chemistry work against buried pipe from the day a home is built, and the risk profile changes depending on which side of town you live on.

• Expansive clay east of I-35. The Blackland Prairie soils under much of East and Northeast Austin, Pflugerville, and Round Rock are among the most expansive clays in the country. They swell with rain and shrink hard in drought, and every cycle flexes the slab and the rigid copper lines beneath it until something gives.
• Limestone and thin rocky soil to the west. In the Hill Country side of town, including Lago Vista, Jonestown, Lakeway, and much of Northwest Austin, pipes are often laid close to rock. A copper line resting against limestone wears at that contact point every time the line expands, contracts, or vibrates, until a pinhole opens.
• Hard water. Water from the Highland Lakes and local wells typically measures moderately hard to hard. Over decades, that mineral content scales up pipe interiors and drives the pitting corrosion that eats pinholes through copper.
• Drought and deluge cycles. Central Texas swings between multi year droughts and flooding rains. The 2022 through 2023 drought shrank clay soils dramatically, and the wet cycles that follow swell them back. Slabs and under slab plumbing absorb that movement.
• Hard freezes. Winter Storm Uri in 2021 and the 2023 ice storm stressed thousands of Central Texas plumbing systems. Some of the damage showed up immediately. Some of it weakened pipes that are only failing now.
• The age of the housing stock. Homes built from the 1960s through the 1980s in neighborhoods like Allandale, Crestview, Balcones, Northwest Hills, and Milwood, and the first waves of Cedar Park, Leander, and Round Rock, commonly have copper water lines and cast iron drains under the slab. Copper of that era is reaching the end of its service life, and cast iron drain lines typically last 50 to 70 years. The math is not in their favor.
• High water pressure. Parts of the Hill Country and lake area run high static pressure because of elevation changes in the distribution system. Anything sustained above about 80 psi accelerates wear on every joint and fitting in the house.

How We Pinpoint a Slab Leak Without Breaking Concrete

Guesswork is expensive when the pipe is under four inches of concrete. Our detection process is designed to end with an X on your floor, not a maybe.

1. Confirm and isolate. We verify the leak with your meter, then pressure test the hot and cold water systems separately to determine which line is losing water. For suspected drain leaks, we perform a hydrostatic test, isolating the sewer system at the cleanout and watching whether it holds water. Homes without an accessible cleanout get one installed, something our sewer line cleanout team handles routinely on older Austin homes.
2. Map the lines. Electronic line tracing lets us map exactly where your pipes run under the slab, which is rarely where the builder's drawings say they do.
3. Listen and look. Ground microphones amplify the specific acoustic signature of water escaping a pressurized pipe. Thermal imaging picks up the heat plume of a hot line leak through the flooring. For sewer lines, a sewer camera inspection lets us watch the failure from inside the pipe and record exactly what we find.
4. Mark it and price it. We mark the leak location, walk you through every repair option, and hand you written upfront pricing before any repair work begins. The quote you approve is the price you pay.

Detection typically takes one to two hours. You do not need to move furniture out or leave your home, and nothing gets opened up during detection.

Slab Leak Repair Options and When Each One Makes Sense

Most companies will tell you what they can do. We think you deserve to know what you should do, because the right answer depends on your pipe, your home, and your plans.

Spot repair through the slab

We open the concrete at the marked location, make the pipe repair, pressure test it, and close it back up. This is the fastest and usually the least expensive full repair, and it is the right call when the leak is a one off in an otherwise healthy line. It is the wrong call when the pipe shows widespread corrosion, because you will be paying to open the floor again next year for the next pinhole.

Rerouting the line

Instead of digging to the leak, we abandon the failed under slab section entirely and run a new line overhead through the attic and walls, typically in PEX or copper. Your floors stay untouched. This is our usual recommendation when a leak sits under a kitchen island, a finished bathroom, or flooring you love, and for copper systems with a history of pinhole leaks. A rerouted line also puts the plumbing somewhere serviceable for the next 50 years instead of back under concrete.

Epoxy pipe lining

Where pipe condition and layout allow it, an epoxy liner cured inside the existing line seals leaks with no demolition at all. It is priced per foot and shines in situations where opening floors or tunneling is impractical.

Tunneling under the slab

For some repairs, especially sewer lines, our excavation crew tunnels in from outside the foundation and makes the repair from below. Your interior stays completely intact. It costs more in labor, and it is worth every penny to homeowners who do not want a jackhammer anywhere near their travertine.

Whole home repipe

When a system has failed two or three times, the honest recommendation is to stop funding a pipe subscription and repipe the water distribution system in one project. We will show you the break even math so the decision is yours.

When the Slab Leak Is a Sewer Line, Not a Water Line

Roughly half the slab leaks we investigate turn out to be drain lines, not pressurized water lines, and they call for a different playbook. Cast iron drains under 1960s through 1980s Central Texas slabs are hitting the end of their 50 to 70 year lifespan right now, and when they rust through, the escaping wastewater swells the clay beneath the foundation for years before anyone notices.

• Diagnosis starts inside the pipe. A sewer camera inspection shows us the exact condition and location of the failure, and a hydrostatic test at the cleanout proves whether the system holds water.
• Sometimes the line can be saved. If the pipe is structurally sound but choked with decades of buildup, hydro jetting restores full flow without excavation, and a spot repair handles an isolated break. Our sewer line services team covers the full range.
• Sometimes it cannot. Collapsed or badly channeled cast iron under a slab usually means sewer line replacement, typically via tunneling so your floors never come up. We show you the camera footage either way, so you are deciding based on what the pipe actually looks like, not on our word.

If your drains have been backing up repeatedly and drain cleaning only buys you a few weeks at a time, treat that as a slab leak warning sign, not a maintenance annoyance.

What Slab Leak Repair Costs in Austin

The companies at the top of the search results will not put numbers on this page, so here is some real context. The ranges below are industry averages for the Austin market in 2026. They are not Lantz Home Services prices, and your home may come in below or above them. Our actual price is always a written, itemized quote you approve before any work begins.

A note on these numbers: they reflect what the broader Austin market typically charges, not our rate sheet. We publish them because we think you should walk into any estimate, ours included, knowing what is normal. The only number that applies to your home is the written quote we hand you after detection.

For perspective on the cost of waiting: prolonged slab leaks routinely lead to foundation repairs running $10,000 to $20,000 or more, plus mold remediation and flooring replacement. The most expensive slab leak is the one you find six months late.

Will Insurance or the City Help Pay for This?

This is the question everyone asks and almost no plumbing website answers. Here is the honest picture.

• Homeowners insurance. Most Texas policies treat a slab leak as sudden and accidental water damage, which means they typically cover the resulting damage and often the cost of tearing out and restoring flooring or concrete to reach the pipe. The pipe repair itself is usually on you, and leaks the adjuster deems long term or gradual are frequently denied. Documentation decides these claims. Our detection report, photos, and itemized invoice are written with your adjuster in mind, because we have been supplying them to Central Texas insurers for decades.
• Your water bill. Austin Water offers billing adjustments for qualifying leaks once you can show the leak was repaired. Several area utilities, including those serving Lago Vista, Cedar Park, and Round Rock, have similar programs. We provide the repair documentation you need to apply. On a slab leak that ran for two months, that adjustment alone can be worth hundreds of dollars.

What Happens After the Repair

A slab leak job is not done when the pipe stops leaking. Before we leave, we pressure test the repair, confirm your meter sits dead still with the water off, and walk you through everything we did. Concrete opened for a spot repair is patched and ready for flooring. If drying equipment or mold remediation is needed, we tell you plainly and can point you to people we trust. You also get a complete documentation packet, including the detection findings, photos, and the itemized invoice, for your insurance claim and your utility adjustment. And the work is warrantied, in writing.

How to Prevent the Next Slab Leak

• Keep water pressure between 50 and 70 psi. A $15 gauge on a hose bib tells you where you stand. If you are sustained above 80 psi, a pressure reducing valve is the cheapest slab leak insurance you can buy.
• Treat your hard water. A softener or conditioner slows the scale and pitting that destroy copper from the inside.
• Water your foundation in drought. It sounds strange to newcomers, but soaker hoses placed about 15 inches from the slab, run during dry spells, keep clay soils from shrinking away from the foundation and flexing your plumbing. Central Texans have done this for generations for good reason.
• Get an annual plumbing inspection if your home was built before 1985. Ten minutes with a meter and a pressure gauge once a year catches most problems while they are still small.
• Know your shutoff and watch your bill. Everyone in the house should know where the main shutoff is, and a $50 smart leak monitor on the main line will text you the moment usage looks wrong.

Leave It to Lantz: Trusted Under Central Texas Homes Since 1972

Lantz Home Services has been a family owned Central Texas company since 1972. That is more than five decades of working under the same slabs, in the same soils, with the same hard water that causes these leaks in the first place. When our plumbers tell you a 1978 Allandale ranch probably has a hot side copper leak near the water heater, it is because we have fixed that exact leak in that exact floor plan more times than we can count.

• Licensed and accountable. Texas plumbing license M-40190, HVAC license TACLA3825C, electrical license TECL 9010.
• Upfront written pricing. You approve the exact price before work begins. No surprises on the invoice, ever.
• Repairs that respect your home. We open concrete as a last resort, not a first move, and we treat your floors like our own.
• Warrantied work backed by a company that has answered its phone in this community for over 50 years.

Slab Leak Service Across Greater Austin and the Highland Lakes

We provide slab leak detection and repair throughout Austin and the surrounding communities, including Lago Vista, Jonestown, Point Venture, Cedar Park, Leander, Round Rock, Lakeway and the Lake Travis area, Spicewood, Marble Falls, and Horseshoe Bay. If you are anywhere in Central Texas and hearing water you cannot find, call us.