A slab leak is the plumbing problem people put off longest, because nothing visible is broken. The water is under the concrete, the house looks fine, and the only evidence is a bill that crept up. That delay is what makes it expensive: by the time it is obvious, the water has usually been running for months.
This guide covers what each option costs around Wilmington, and which one is worth choosing. For the repair itself, see slab leak detection and repair in Wilmington.
What it costs
| Scope | Typical price |
|---|---|
| Electronic leak detection and pinpointing | $150 to $600 |
| Spot repair through the slab, single leak | $1,500 to $4,500 |
| Reroute of a single failed line, PEX overhead | $1,500 to $4,000 |
| Whole house repipe after repeat leaks | $4,000 to $9,500 |
| Concrete cutting, patching, and finish restoration | $400 to $1,800 on top |
| Flooring replacement over the opened area | Varies by material, often the largest line |
Ranges are typical for the Wilmington area and are not a quote. Detection is usually credited against the repair when the same contractor does both, so ask before you pay for it separately.
The three ways this goes
1. Spot repair through the slab
The plumber pinpoints the leak, cuts and jackhammers through the concrete, repairs the pipe, and patches the slab. This makes sense when the leak is accessible, the rest of the system is in good condition, and what is on top of the slab is cheap to put back.
It is the wrong choice when the floor above is tile, hardwood, or stained concrete, because restoring the finish frequently costs more than the plumbing did. It is also the wrong choice if this is the second leak, because the third is coming.
2. Reroute the line overhead
The failed line under the slab is abandoned in place and a new PEX line is run overhead through the attic and dropped down inside the walls to the fixtures it serves. No concrete gets cut. The tradeoff is drywall patching where the drops come down, and attic work.
For a single failed line this is usually the best value in this market, and it is what most experienced local plumbers will recommend first. One local caution: an attic line in coastal Carolina needs proper insulation and routing away from soffit vents. Trading a slab leak for a freeze risk is a real failure mode, and our frozen pipes guide explains why attic runs are more exposed here than people expect.
3. Repipe the house
Once you have had two leaks under the same slab, you are no longer dealing with an incident, you are dealing with a system at end of life. Every line under that concrete is the same age, the same material, and sitting in the same soil. Chasing them one at a time costs more in total than replacing them all and it comes with repeated disruption.
A full repipe abandons the under slab lines entirely and runs new PEX overhead. See the Wilmington repipe cost guide for what that involves.
What makes a quote go up here
- A high water table. Much of the coastal plain has groundwater close to the surface. Water in an excavation has to be managed before anyone can work, and that adds time to a slab repair that an inland contractor would not price in.
- Finished flooring. Tile, hardwood, and stained concrete are often the largest single line on the invoice, and they are the main reason rerouting beats spot repair.
- Leak location. A leak under an exterior wall, a kitchen island, or a load bearing section is materially harder than one under open floor.
- Hot side versus cold side. Hot lines fail first and more often, because heat accelerates both corrosion and the expansion cycling that wears pipe against concrete.
- How long it ran. A leak found in week one is a plumbing bill. A leak found in month eight can involve subfloor, cabinetry, and mold remediation.
Where these actually happen around Wilmington
Slab leaks are not evenly distributed across this market, and knowing that saves people from worrying about a problem their house structurally cannot have.
Wilmington's older neighborhoods are predominantly crawl space construction, so a failing supply line there shows up as a wet crawl space, not a warm floor. Slab on grade is far more common in the Brunswick County communities around Leland, most of which were built after 2000. That is also why polybutylene is rare there and slab leaks are not: different era, different problem. In the Greenville market the same split runs between the older crawl space housing near uptown and the newer slab subdivisions toward Winterville and south Greenville.
Before you call anyone
- Shut off every fixture and watch the water meter. If the dial keeps moving, you have a leak somewhere. This is free and it is the single most useful thing you can do.
- Compare your last three water bills. A slab leak shows as a step change, not a gradual climb.
- Walk the floors barefoot. A hot line leak often produces a genuinely warm patch.
- Photograph any damage before work starts. Insurers ask, and the answer is much better if you have it.
- Ask every bidder to price both spot repair and reroute. A contractor who will only quote one of the two is not giving you the information you need.