Slab Leak Repair Cost
Detection alone runs $350 to $800. Detection plus repair typically lands between $1,200 and $4,500. Rerouting the line instead of cutting the slab runs $1,500 to $5,000 and often costs less over a decade on an older system.
Cost breakdown
National baseline ranges. Any state guide re-prices these for local labour costs.
| Item | Typical low | Typical high | Notes |
|---|---|---|---|
| Leak detection | $350 | $800 | Acoustic and thermal; often credited against the repair |
| Spot repair through the slab | $1,200 | $3,500 | Cut, repair, patch. Flooring restoration usually separate |
| Reroute the affected line | $1,500 | $5,000 | Abandons the under-slab run entirely |
| Post-tension cable scanning | $300 | $800 | Required before cutting a post-tension slab |
| Whole-house repipe (overhead) | $4,000 | $15,000 | When multiple under-slab failures make spot repairs futile |
| Flooring removal and replacement | $500 | $4,000 | Tile, hardwood, and stone at the top of the range |
| Concrete patching | $300 | $1,200 | Sometimes included in the plumbing quote; confirm |
| Water damage restoration | $1,000 | $6,000 | If the leak went undetected for a long period |
Editorial estimates for orientation, not quotes. Always get a written estimate before work begins.
What drives the price
- Detection accuracy
- The single biggest cost lever. Precise location means one small opening; a poor locate means several
- Foundation type
- Post-tension slabs, common in Texas, Arizona, and Nevada, require cable scanning before any cutting
- Flooring above
- Cutting through tile, hardwood, or stone adds material and restoration cost well beyond the concrete work
- Repair approach
- Spot repair is cheaper today; rerouting costs more up front and removes the whole failure category
- Number of leaks
- A second leak in the same system usually shifts the economics decisively toward rerouting or repiping
Detection first, always
Detection is priced separately from repair for a good reason: it is the step that determines what the repair costs. Precise acoustic location means one modest opening in the concrete. Guessing means opening several and patching all of them.
Do the free diagnostics first. A meter test, a dye test on every toilet, and a day with the irrigation off will rule out the far more common explanations for the same symptoms. Only pay for slab detection once those come back clean.
Repair in place or reroute
A spot repair fixes the failure that happened. A reroute abandons the under-slab pipe and runs a new line overhead or around the foundation, removing the entire category of failure.
The case for rerouting is that the pipe elsewhere under the slab is the same age, same material, and same condition as the section that just failed. On an older copper system that has already leaked once, the second leak is generally a matter of timing rather than luck, and each one costs another detection plus another concrete opening.
For a young system with a single leak from a clear localized cause, a spot repair is reasonable. For a system that has leaked twice, rerouting or repiping is usually the honest recommendation.
Post-tension slabs need special handling
Post-tension foundations contain steel cables under high tension, and they are common in Texas, Arizona, Nevada, and parts of California. Cutting one is a serious structural event, not a minor mistake.
Any concrete work on a post-tension slab must be preceded by scanning to locate the cables, which adds $300 to $800. A plumber who proposes cutting a post-tension slab without scanning should not proceed, and this is worth asking about directly if your home is in one of those states.
Frequently asked questions
Is detection worth paying for separately?
Yes, and it usually saves more than it costs. The alternative is exploratory cutting, where each wrong opening costs concrete work, flooring, and patching. Many companies credit the detection fee against the repair if you use them for both, so ask.
Will insurance cover a slab leak?
Coverage varies genuinely by carrier and state. Many policies cover the resulting damage and the cost of accessing the pipe, meaning the concrete cutting, while excluding the pipe repair itself. Gradual-damage exclusions are frequently invoked, so document when you first noticed symptoms and report promptly.
How long can I leave a slab leak before fixing it?
Not long, and the reason is structural rather than financial. Escaping water erodes the soil supporting the foundation and, in expansive clay, causes localized swelling. Both remove uniform support from the slab. A confirmed slab leak should be addressed within days, not months.
Can I just cap the line instead of repairing it?
Sometimes, if the leaking line serves a fixture that can be re-fed from elsewhere, capping and rerouting that branch is a legitimate and economical solution. It is worth asking about, particularly for a leak on a line serving a single fixture rather than a main distribution run.
Related cost guides
- Whole-House Repiping CostWhat it costs to replace a home's supply piping, how PEX and copper compare, and the scope question that causes most disputes.
- Burst Pipe Repair CostWhat burst pipe repair costs by location and pipe type, plus the water damage costs that usually exceed the plumbing.
- How Much Does an Emergency Plumber Cost?What emergency plumbing actually costs, how after-hours premiums work, and which problems are cheaper to schedule for morning.
Related services
- Slab Leak Detection and RepairLocation and repair of water lines leaking beneath a concrete foundation, using acoustic and thermal detection to minimize concrete work.
- Emergency Leak DetectionNon-invasive location of hidden water leaks behind walls, under floors, and beneath slabs using acoustic, thermal, and pressure testing equipment.
- Whole-House RepipingReplacement of a home's supply piping where the existing system has reached end of life, using PEX or copper.
Common questions
Related articles
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- The First Ten Minutes of a Plumbing EmergencyWhat you do before the plumber arrives determines most of the damage. The order of operations that limits it.
- Why Pipes Burst in Cold States and Catastrophically in Warm OnesMinnesota freezes harder than Texas every year and loses fewer pipes. The reason is preparation, not temperature.