Copper pipe leaks under the slab
Under-Slab Copper Pipe Leak Repair Services in Texas
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Copper has served Texas homes for decades, and it is the pipe most often found under older slabs. When it leaks, the cause is usually slow wear from the water, the soil or the slab itself. Call and we’ll connect you with a local Texas crew for copper pipe leak repair under the slab.
Tell us about the home and we’ll connect you with a local crew.
Why copper pipe under a slab leaks
Copper is durable, which is why it was used in so many homes. It is not permanent. Under a slab, a few things tend to wear it down:
- Water chemistry. Water that is aggressive, hard or treated in certain ways can slowly thin the inside wall of the pipe. Pinhole leaks are the typical result.
- Abrasion. Pipe that touches concrete, rock or other pipe can rub through the wall as the slab and soil move.
- Movement. Seasonal shifts in the ground push and pull on lines that sit tight against the slab.
- Vibration and pressure changes. Water hammer and pressure surges flex pipe and fittings over the years.
- Installation details. Bends, joints and the way the pipe was bedded and sleeved affect how it ages.
Usually it is a combination, acting over decades.
Signs of a copper line leak under the slab
- A warm spot on the floor where a hot-water line runs. See warm spot on the floor.
- A water bill that climbs without a change in use. See high water bill.
- The sound of running water with everything off, or a hissing sound from a floor or wall.
- A moving water meter with all taps and appliances off.
- Damp carpet, a musty smell or lifting flooring.
- Low water pressure at some or all fixtures.
Copper conducts sound and heat well, so slab leaks in copper often announce themselves. Some are quiet and show only on the meter or the bill.
Describe what you’ve noticed.
How a copper line leak is located
The technician first isolates the line, closing sections of the plumbing and watching for pressure loss to work out which line is leaking. Because copper carries sound and heat, acoustic listening equipment and thermal imaging are particularly useful. A pipe locator traces where the line runs, and the leak is marked on the floor before any work starts.
See slab leak detection for the full sequence.
Repair options for copper lines
Spot repair
The slab is opened over the leak and the damaged section is replaced or fitted. Good for a first, well-located leak. See spot repair.
Reroute
The leaking line is abandoned and a new one is run above the slab. Avoids opening the floor. See rerouting.
Pipe lining
On some copper lines, the inside is cleaned and coated. See pipe lining.
Repiping
When copper has leaked more than once, replacing some or all of it is worth discussing. See repiping.
A technician can locate it before any floor is opened.
Copper under slabs in Texas homes
Homes in the Dallas-Fort Worth suburbs and elsewhere across the state that were built from the 1960s through the 1980s very often have copper under the slab. Expansive clay moves the slab and the pipe against each other, and it can wear a line over decades. In Central and West Texas, hard water and mineral buildup add to the wear. In Houston-area homes, wet soil around the line can speed external corrosion.
Technicians generally ask about the home’s age, the water source and any past leaks before suggesting an approach. If one line has leaked, the rest of the copper installed at the same time is usually of the same age.
Spot repair, reroute, lining or repiping, explained for your line.
What to expect once a leak is found
The technician should explain which line is leaking, how it was located and what the options are before work begins. Water is shut off for part of the job. After the repair, the line is pressure tested. If water reached floors, cabinets or walls, a restoration company handles drying and cleanup, and flooring contractors handle replacement.
Ask about the condition of the pipe next to the leak. A technician who sees thin walls or heavy scale at the repair site can tell you whether the rest of the line looks similar, and that is useful information for deciding between repair and replacement.
Describe the signs you have seen.
Types of copper pipe
Copper supply pipe in homes is usually one of three types, which differ mainly in wall thickness. Type K has the thickest wall and is often used for the main service line underground. Type L has a medium wall and is common for supply lines in and under houses. Type M has the thinnest wall and was widely used in many homes.
Wall thickness matters under a slab. A thinner wall has less material to lose to corrosion from the inside or wear from the outside, so a pinhole can open sooner. That does not mean every Type M line will leak, but it is one of the factors a technician considers when a line has started to fail.
Copper also comes as soft, rolled tubing or as rigid lengths. Soft copper can be run under a slab in long pieces with few joints, while rigid lengths need fittings where they meet. Where you have joints under the slab, those are common leak points. The pipe type is sometimes printed on the copper in colored ink, which may be visible near the water heater.
Pinhole leaks
Many copper leaks under slabs start as pinholes, very small openings that let a fine spray or seep escape. They can be hard to hear and may only show on the meter at first. Where one pinhole appears, others can follow along the same line, which is worth keeping in mind when choosing a repair.
Ask the technician whether the line showed more than one weak point during testing. If it did, that may point toward a reroute instead of a single repair.
Copper pipe leak questions
Slow wear from the water on the inside, abrasion and movement on the outside, and sometimes a combination of both. Pinholes are a common result when a thin section of wall finally gives way.
If your home was built in the 1960s through the 1980s, the copper is probably as old as the house. A technician can confirm the material and condition when they find the leak.
Not always, but the rest of the pipe is the same age and was exposed to the same water and soil. A repair at one point does not change the state of the rest, so ask the technician about the condition of the pipe near the leak.
Yes. A leak can be fixed in place, rerouted around or, on some lines, lined. Whether any of these suits you depends on the leak and the line.
Yes. Copper and PEX are both common in Texas repipes. Ask your contractor why they recommend one over the other for your house.
Only hot-water lines do. A leak on the cold side shows in other ways, such as the meter, the bill or a damp floor. See cold-water slab leaks.
Not reliably. Signs like warm floors, sounds and meter movement point to a leak, but a technician confirms which line and where.
It can contribute, through scale and through how the water interacts with the pipe over time. The topic has its own page on hard water and copper leaks.
Check the meter with everything off. If it moves, call for detection before choosing a repair.
Get the copper line checked
Call and we’ll connect you with a local technician who can find the leak and explain the repair options.
A local crew knows how homes in your area are usually plumbed.