PEX slab leaks
PEX Slab Leak Repair Services in Texas
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PEX is the plastic supply pipe used in most newer Texas homes. It does not corrode like metal, and it can still leak under the slab, usually at a fitting or where the pipe has been stressed. Call and we’ll connect you with a local Texas crew for PEX slab leak repair.
Tell us about the home and we’ll connect you with a local crew.
What PEX is
PEX is cross-linked polyethylene, a flexible plastic pipe used for water supply lines. It came into wide use in homes from the 1990s and is now the standard in much new construction. It is usually color-coded, with red for hot water and blue for cold, and it is joined with crimp rings, clamp rings or expansion fittings.
In slab homes, PEX lines may be run beneath the concrete, sometimes in sleeves and sometimes in direct contact with the slab and soil. Many newer systems use a manifold, a central point from which individual lines run to each fixture, which means fewer joints in the slab.
Where PEX leaks happen
- Fittings. Most PEX leaks are at the joints. A poorly seated fitting, a crimp that was not made correctly, or a ring that has shifted over time can all leak.
- Kinks and bends. A tight bend or a kink can stress the pipe wall and cause a leak or a weak spot.
- Damage during construction. Pipe can be nicked or crushed when the slab was poured or when other trades worked nearby.
- Sunlight before installation. PEX stored in the sun for long periods before it was installed may be weakened.
- Abrasion and movement. Seasonal soil movement can rub lines against concrete or rock.
- Pressure and heat. High water pressure or very hot water can put additional strain on fittings and pipe.
PEX generally does not pit or corrode, so the pinhole wear common in older copper is less of a concern.
Describe what you’ve noticed.
Signs of a PEX leak under the slab
The signs are those of any slab leak: a moving meter with everything off, a higher water bill, the sound of water, damp or warm flooring, or low pressure. A hot-water PEX line may produce a warm spot on the floor, though PEX does not conduct heat the way copper does, so the spot may be fainter. See warm spot on the floor and water meter leak check.
How a leak in PEX is located
The first step is the same as for any line: isolate sections and check for pressure loss to find out which line is leaking. Pinpointing the spot is harder in plastic, because PEX does not carry sound or heat like metal. The technician may use acoustic listening, thermal imaging and other methods, and often combines them. Because the pipe is not metallic, line locators that depend on metal work differently.
Experience matters. Ask whether the technician has found leaks in PEX before and what they will use. The location is marked on the floor before anything is opened. See slab leak detection.
A technician has methods for locating leaks in PEX.
Repair options for PEX lines
Spot repair
The slab is opened over the leak and a fitting or section is replaced. PEX is easy to splice with the right fittings, so repairs are practical. See spot repair.
Reroute
The leaking line is abandoned and a new one is run above the slab, avoiding the floor. If the system uses a manifold, a reroute may be a short job. See rerouting.
Repiping
If several lines are involved, replacing more of the system may be discussed. See repiping.
Pipe lining is generally not used for PEX.
PEX in Texas homes
Homes built since the late 1990s, including much of the growth around Frisco, Prosper, McKinney, Cypress, Katy, Kyle and Leander, are more likely to have PEX than copper. Expansive clay and fast-draining or wet soils all affect lines under a slab, and newer homes can see leaks from construction damage or fittings that were not seated correctly.
In a newer home, a leak is also a question to raise with the original builder if the home is still under a builder’s warranty. Check the terms.
Spot repair or reroute, explained for your line.
Questions worth asking
- What is the leak’s location, and how did you find it?
- Is it at a fitting or in the pipe?
- Are other fittings nearby likely to be an issue?
- Does the system have a manifold, and where is it?
- Would a reroute be practical?
- How will the repaired line be tested?
Describe the signs you have seen.
Manifold and home-run systems
Many PEX homes use a manifold. Instead of one main line branching off to each room, individual lines run from a central manifold to each fixture or group of fixtures. This is sometimes called a home-run layout.
A manifold changes how a leak is found. Each line can often be shut off and tested on its own at the manifold, which can narrow a leak to one run quickly. Labels on the manifold, if they were filled in when the house was built, show which line feeds which fixture.
It also changes the repair options. If one run under the slab leaks, it may be possible to abandon that run and replace it with a new line through the walls or attic, without opening the floor and without touching the other lines. That is rerouting limited to a single fixture. See slab leak reroute.
Not every PEX home has a manifold. Some use a trunk-and-branch layout like older copper systems, with fittings under the slab where branches split. A technician can usually tell which layout you have from the water heater area and the fixture connections.
PEX fittings and connections
Most PEX leaks are found at connections. Fittings may be crimped, clamped or expanded, depending on the system the installer used, and each relies on being made correctly at the time. A fitting that was not fully seated can hold for years before it starts to seep. Under a slab, fittings are usually where branches split. Tell the technician if you know which system your home uses.
PEX can also be damaged by sunlight before installation, by rodents in attics and crawl spaces, or by sharp edges where it passes through framing. Under a slab, these causes are less common than fitting failures.
PEX slab leak questions
Yes. Most leaks are at fittings, and some come from kinks or damage during construction. PEX does not corrode like metal, but it can still fail.
PEX avoids the pinhole wear that affects older copper, and it has fewer joints in many systems. It still has its own weak points, mainly fittings and installation damage.
The technician isolates the line, then uses acoustic listening, thermal imaging and other methods. Plastic does not carry sound or heat as metal does, so experience matters.
Yes. The slab is opened, the damaged section or fitting is replaced and the line is tested. PEX can be spliced with the right fittings.
A hot-water line can, but the spot may be fainter than with copper. A meter that moves with everything off is a more reliable sign.
Homes built since the late 1990s are more likely to, though many were plumbed with copper. A technician can confirm.
PEX is often red for hot and blue for cold, with white or other colors used in some systems. The color helps identify the line, and it does not describe the quality of the pipe.
If the home is under a builder’s warranty, check its terms. A technician’s findings can help describe what happened.
Pipe lining is generally not used for PEX. Spot repair, reroute and repiping are the usual options.
Get the PEX 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.