The short answer
The three common options are a spot repair through the slab, a reroute that abandons the leaking line and runs new pipe through walls or attic, and a repipe of the whole supply system. A spot repair fits a single leak in otherwise sound pipe. A reroute fits a line with several leaks or hard access. A repipe fits a house where the pipe is failing everywhere.
The decision starts with detection. A plumber confirms which line leaks, pinpoints the spot and checks the rest of the system. That tells you whether one leak is a fluke or the first of many.
The three options compared
Each has a different disruption and a different future.
| Option | How it works | Disruption | Best when |
|---|---|---|---|
| Spot repair | Cut the slab above the leak, replace the section | Concrete cutting, floor repair | One leak, sound pipe elsewhere |
| Reroute | Cap the old line, run a new one overhead | Wall and attic work, slab untouched | Multiple leaks on one line or hard access |
| Repipe | Replace the supply system | Largest scope, least repeat risk | Widespread pinholes and old pipe |
See slab leak repair for the full service.
Spot repair: what it involves
The plumber marks the leak, cuts and removes a small section of concrete, exposes the pipe and replaces the damaged piece. The concrete is patched, and flooring above is repaired by the right trade. The job is quick for one leak, but it opens the floor.
Ask about flooring. Tile and wood need matching, and the patch may be visible. If other lines under the slab are the same age, the leak may repeat elsewhere.
Reroute: leaving the slab alone
A reroute abandons the leaking line under the slab and installs a new line in the wall or attic. The slab stays intact, and the new route is accessible for future repairs. It takes more pipe and more wall work, but it avoids cutting concrete.
Rerouting is common when a line runs under a finished floor that is expensive to repair. It also works when detection shows several leaks on one branch, since that line is clearly failing.
Repipe: when the whole system is tired
If leaks have appeared in more than one place or the pipe is old throughout, a repipe replaces the supply system. It costs more up front and reduces the chance of repeating the same call. See repiping for how it is planned.
Plumbers recommend repipes when a house has had several repairs and the next one looks likely. It is a long-term decision, and the quote should show the repipe alongside the repair options so you see the trade-offs.
Signs that point to a slab leak
A hot spot on the floor, a sudden jump in the water bill, the sound of running water when everything is off and damp carpet along a wall are the usual signs. Any one of them is a reason to test. Two together make a slab leak likely.
A quick home check helps. Turn off every fixture and watch the water meter. If the dial keeps moving, water is escaping somewhere. Then close the main valve at the house and watch again. If the dial stops, the leak is inside the house lines. If it keeps moving, the leak is on the line between the meter and the house.
What to do while you wait for the visit
Shut off the main valve if water is visible or the floor feels warm and wet. Switch off the water heater at its breaker or gas control so the tank does not run dry while you are without supply. Move rugs and furniture off damp areas.
Take photos of any damage and note when you first saw each sign. Insurers often ask for dates, and a plumber can use the timeline to narrow the search. Keep the detection report, because it supports any claim you make.
Weighing cost against risk
The cheapest option today is not always the cheapest over ten years. A spot repair on a line that is failing in several places can lead to a second slab cut within a few years. A reroute costs more now and avoids that risk on the abandoned line.
A repipe is the largest outlay and gives the longest runway. Ask the plumber to put the three options in writing, with the scope and the finish work each one includes, so you can compare them side by side.
Standards for repairs under a slab
Slab repairs follow the California Plumbing Code, based on the Uniform Plumbing Code (UPC), and use materials certified to NSF/ANSI 61. A pressure test confirms the repair, and some plumbers leave a pressure gauge on the line for a day to be sure.
Ask how the work will be tested and documented. A record of the test is useful for insurance and for a future home sale.
Santee note: age of the housing and permits
Santee's population grew from under 2,000 in 1950 to 25,750 in 1970, and a lot of housing went up in those years. Lines installed then are now five decades old or more, which is the age range where slab leaks start to become common. A single slab leak in a house of that age often means the rest of the system is aging too.
The City of Santee's page on work not requiring a permit says that replacing a failed concealed water pipe is new work needing a permit. A slab repair or reroute involves concealed pipe, so ask Planning and Building what your project needs.
Sources: City of Santee history page, City of Santee, Work Not Requiring a Building Permit.
What to ask the plumber
These questions bring the trade-offs into focus.
- How did you find the leak?Look for acoustic and thermal detection plus a pressure test.
- Are other lines at risk?A pressure test can reveal weak lines.
- What will the floor look like afterward?Ask who repairs flooring and what finish to expect.
- Is a permit needed?Concealed pipe replacement may need one.
- Will I see a quote for each option?You should.
Slab leak suspected?
Call the 24/7 line to start detection.
Slab leak options questions
No. It wastes water, can undermine soil and can lead to mold.
Coverage depends on the policy and the cause. Ask your insurer and keep the detection report.
It depends on the access and the floor finish. Ask for quotes on each.
Yes. See leak detection.
Yes. See our El Cajon page for details.