Slab Leak Repair in Marble Falls, TX

Slab leaks are more common in the Highland Lakes than almost anywhere in Texas. We find them fast and fix them right, minimizing damage to your home and your budget.

A slab leak, a leak in the water supply or drain lines running beneath or through the concrete foundation of your home, is one of the most serious plumbing problems a Highland Lakes homeowner can face. The limestone geology, hard water, and aging pipe infrastructure of the region make slab leaks more common here than in most other parts of Texas. Knockout Plumbing Services specializes in slab leak detection and repair throughout the Highland Lakes, using proven diagnostic methods to locate leaks precisely and repair them with minimal disruption to your home.

What's Included

Our Process

Detection

We use acoustic equipment and pressure testing to locate the slab leak precisely, often within a few inches, before any concrete is cut.

Repair Options

We present the repair options for your specific situation: targeted under-slab repair, pipe rerouting through walls or attic, or epoxy lining where applicable.

Repair

We complete the repair using the method that best balances cost, disruption, and long-term reliability for your home.

Testing and Restoration

We pressure test the repaired system, patch the concrete, and advise on flooring restoration and moisture remediation if needed.

The Slab Leak Problem in the Highland Lakes

If you own a home in the Highland Lakes that was built before 1990, there is a meaningful probability that you will experience a slab leak at some point during your ownership. This is not a reflection of poor construction, it is a consequence of the specific combination of geology, water chemistry, and pipe age that characterizes the region.

The Edwards Plateau limestone that underlies most of the Highland Lakes region is a beautiful and distinctive geological feature, but it creates specific challenges for residential plumbing. Unlike the deep clay soils found in other parts of Texas, the limestone substrate is relatively rigid and does not compress uniformly under the weight of a home. As the limestone weathers and the soil above it settles, the concrete slab can experience differential movement, one part of the slab moving slightly relative to another. This movement stresses the pipes embedded in or running beneath the slab, particularly at joints and bends, eventually causing them to crack or separate.

The hard water compounds the problem. The water in Marble Falls, Kingsland, Burnet, and surrounding communities is classified as “very hard” to “extremely hard,” with mineral content typically ranging from 300 to 400 parts per million. This mineral-rich water attacks copper pipe from the inside through a process called pitting corrosion, creating small pits in the interior wall of the pipe that deepen over time until they penetrate the pipe wall. In a pipe that is already stressed by slab movement, this internal corrosion accelerates the development of leaks.

The age of the housing stock is the third factor. A significant portion of homes in the Highland Lakes were built in the 1960s, 1970s, and 1980s, when copper pipe was the standard material for water supply lines under slabs. That copper is now 40-60 years old, well past its typical service life in hard water conditions. The combination of age, hard water corrosion, and slab movement creates conditions where slab leaks are not just possible but expected in older homes.

How We Find Slab Leaks

Pressure Testing and Isolation

The first step in slab leak detection is confirming that a leak exists and isolating which pipe system it is in. We shut off the water supply and pressure test the system to confirm the leak. We then isolate the hot and cold supply lines separately to determine which one is leaking. This isolation also tells us whether the leak is in the supply line under the slab or in a more accessible location.

If the pressure test confirms a leak in the under-slab piping, we proceed to acoustic detection to locate it precisely. Knowing which pipe system is leaking, hot or cold, supply or drain, allows us to focus the acoustic scan on the correct pipe path, reducing the time needed to locate the leak.

Acoustic Leak Detection

Water escaping from a pressurized pipe creates a distinctive sound, a hissing or rushing noise that is transmitted through the pipe, the surrounding soil, and the concrete slab. Professional acoustic detection equipment amplifies this sound and allows us to locate the leak by scanning the floor surface and identifying the point of maximum sound intensity.

Acoustic detection is highly effective for slab leaks in supply lines, where the water is under pressure and the leak creates a consistent sound. For drain line leaks, which are not under pressure, we use a combination of pressure testing with smoke or air and visual inspection of the drain system to locate the problem.

The precision of acoustic detection is remarkable, in favorable conditions, we can locate a slab leak to within 6-12 inches of its actual position. This precision is what allows us to make a targeted concrete opening directly over the leak rather than tearing up large sections of flooring.

Slab Leak Repair Options

Targeted Under-Slab Repair

For a single, well-located leak in a pipe that is otherwise in good condition, targeted under-slab repair is often the most cost-effective option. We cut a targeted opening in the concrete, typically 12-18 inches square, directly over the leak, expose the pipe, repair or replace the damaged section, and patch the concrete. The flooring over the repair area needs to be replaced, but the disruption is limited to a small area.

The key to minimizing the disruption of under-slab repair is precise leak location. By using acoustic detection to locate the leak to within a few inches before cutting any concrete, we can make the smallest possible opening and complete the repair efficiently. We always locate the leak precisely before cutting, never the other way around.

Pipe Rerouting

The leaking pipe is in a location that is difficult to access under the slab (near the center of the house, under a load-bearing wall, etc.)
The pipe is old enough that additional leaks are likely in the near future, rerouting addresses the entire pipe run, not just the current leak
The homeowner wants to avoid any disruption to flooring, tile, or foundation
The cost of rerouting is comparable to or less than the cost of under-slab repair plus flooring restoration

Rerouted pipes run through the walls and attic, where they are fully accessible for future inspection and maintenance. The new pipe is typically PEX, a flexible, corrosion-resistant material that is not affected by hard water and has a service life of 50+ years. A rerouted PEX system is effectively a permanent solution to the slab leak problem for that pipe run.

Epoxy Pipe Lining

For drain lines and in some cases supply lines, epoxy pipe lining is a trenchless repair option that involves coating the interior of the existing pipe with a structural epoxy lining. The lining seals existing leaks, prevents future corrosion, and restores the structural integrity of the pipe without any excavation. This method is most applicable for drain lines that have multiple small cracks or leaks, where targeted repair would require multiple concrete openings.

Epoxy lining is not appropriate for all situations, the pipe must be in sufficient condition to hold the lining, and the pipe diameter must be large enough to accommodate the lining process. We assess each situation individually and recommend lining only when it is the best option for the specific pipe and leak condition.

What to Do When You Suspect a Slab Leak

If you notice any of the signs of a slab leak, unexplained water bill increases, warm spots on the floor, the sound of running water when all fixtures are off, or cracks in the foundation, call us immediately at (325) 248-1800. Do not wait to see if the problem resolves itself; slab leaks do not self-heal, and the damage they cause compounds with every day they go unaddressed.

While you are waiting for us to arrive, you can turn off the main water supply to the house to stop the flow of water into the leak. This will not repair the leak, but it will stop the water from continuing to saturate the soil beneath the foundation. The main shutoff valve is typically located near the water meter at the street or at the point where the main line enters the house.

Knockout Plumbing Services provides slab leak detection and repair throughout the Highland Lakes region, including Marble Falls, Kingsland, Burnet, Horseshoe Bay, Llano, Granite Shoals, Meadowlakes, Spicewood, Bertram, and surrounding communities. Call (325) 248-1800 for slab leak service.

Frequently Asked Questions

Why are slab leaks so common in the Highland Lakes?

Three factors combine to make slab leaks unusually common in the Highland Lakes. First, the limestone geology creates a substrate that shifts and settles differently than the clay soils found in other parts of Texas, stressing the pipes embedded in or running beneath the slab. Second, the extremely hard water, 300-400 ppm, accelerates corrosion of copper pipes from the inside through pitting corrosion. Third, many homes in the region were built in the 1970s and 1980s with copper pipe that is now 40-50 years old and reaching the end of its service life in these hard water conditions.

What are the signs of a slab leak?

The most common signs of a slab leak are: unexplained increases in your water bill, the sound of running water when all fixtures are off, warm spots on the floor (from a hot water line leak), cracks in the foundation, flooring, or walls, mold or mildew growth at floor level, and low water pressure throughout the house. If you notice any of these signs, call us immediately, slab leaks cause damage that compounds quickly.

Do you have to tear up my entire floor to fix a slab leak?

No. We use acoustic detection equipment to locate the leak precisely before cutting any concrete, which allows us to make a targeted opening, typically 12-18 inches square, directly over the leak rather than tearing up large sections of flooring. In some cases, we can reroute the pipe through the walls or attic entirely, avoiding any concrete cutting. We always present all options and let you choose the approach that best fits your situation.

Can a slab leak damage my foundation?

Yes. A slab leak that goes undetected for an extended period can saturate the soil beneath the foundation, causing differential settling and cracking. In severe cases, this can cause significant structural damage to the foundation. This is why early detection and repair is so important, the longer a slab leak goes unaddressed, the more damage it causes and the more expensive the total repair becomes.

Will my homeowner's insurance cover a slab leak?

Most homeowner’s insurance policies cover the cost of accessing the leak, cutting the concrete and repairing the pipe, but not the cost of repairing the damage caused by the leak (flooring, drywall, mold remediation). Coverage varies by policy, so we recommend calling your insurance company before we begin work. We can provide documentation of the leak location and repair for your insurance claim.

What is pipe rerouting and when is it the right choice?

Pipe rerouting involves abandoning the leaking pipe under the slab and running a new pipe through the walls, attic, or crawl space to bypass the slab entirely. This approach avoids concrete cutting entirely and is often the right choice when the leaking pipe is in a difficult location, when the pipe is old enough that additional leaks are likely in the near future, or when the homeowner wants to avoid any disruption to flooring or foundation. The new pipe is fully accessible for future maintenance and inspection.

How long does slab leak repair take?

A targeted under-slab repair, locating the leak, cutting the concrete, repairing the pipe, and patching the concrete, typically takes 1-2 days. Pipe rerouting is typically completed in 1 day. More complex situations involving multiple leaks or significant pipe deterioration may take longer. We will give you a realistic timeline before beginning work.

Related Services

Cities We Serve

Knockout Plumbing Services provides this service throughout the Marble Falls area and surrounding communities. Click your city below for local service details.

Request Service

Call us directly or fill out the form. We respond fast.