A slab leak repair company finds the leak first, then repairs or replaces the pipe, and a good one tells you the options before touching the floor. In practice that means locating the leak without breaking concrete, choosing between a spot repair, a reroute or a larger replacement, and handling the permit. This page covers how the work goes and how to compare quotes. For the wider set of leak problems, see our leaks and burst pipes hub. The home page shows how we arrange a visit.
What does a slab leak repair company actually do?
A slab leak company confirms a leak exists, pinpoints where it is under the floor, and repairs it by one of three routes: opening the slab and fixing the pipe, running a new line through walls or the attic, or replacing the failing run. The first step is detection, because breaking concrete in the wrong spot is the costliest mistake.
Detection uses tools that listen for water noise in the pipe, trace the line, and sometimes read heat or pressure changes. After that a plumber gives you the options with prices. Ask for the cause as well: a single pinhole in one old copper line is a different story from a house full of pipes at the end of their life.
Be wary of a pitch that jumps straight to a large replacement before the leak has been confirmed, or one that cannot say where the leak is. A fair quote shows the detection result, where the pipe runs, and why the chosen method fits.
How do I know if I have a slab leak?
Common signs are a water bill that rises with no change in habits, the sound of running water when every tap is off, a warm spot on the floor, damp or lifting flooring, a musty smell, and lower water pressure. None of these is proof alone. A leak can sit elsewhere in the house, so the first check is the meter.
LADWP's method: shut off all water indoors and outdoors, then look at the leak detection gauge on the meter. If it moves with everything off, water is going somewhere. This Old House lists early signs as a small bill increase, faint running-water sounds and minor pressure drops, with warm or damp floor spots and mold as more obvious ones.
Slab-on-grade homes are common in Los Angeles, and many have copper supply lines routed through or beneath the concrete. A hot spot on the floor can point to a leak on a hot water line. If you suspect a slab leak, turn off the water at the main when you leave the house, and call a plumber instead of waiting for the floor to buckle. Our page on why a water bill gets so high explains the other causes.
How do slab leaks get repaired?
There are three main methods. A spot repair breaks the concrete over the leak and fixes the pipe. A reroute abandons the leaking line and runs new pipe through walls or the attic. A repipe replaces the whole run or whole house. Spot repair is usually cheapest, but it only helps when the rest of the pipe is sound.
| Method | What happens | Typical published range | Best when |
|---|---|---|---|
| Spot repair | Cut the slab, repair or replace the section, patch concrete | About $1,500 to $3,500 | One isolated failure in otherwise sound pipe |
| Reroute | New line in walls or attic, old line abandoned | About $2,000 to $5,000, and up to $15,000 on big jobs | The slab is hard to reach or the pipe keeps failing |
| Full repipe | New pipe through the house | Several thousand dollars and up | Many failures, old pipe, or a plan to renovate |
These are national price guides, so treat them as a guide. Los Angeles access, flooring, tile and permit costs can move them. Our slab leak repair cost page goes through the numbers, and slab leak repair or repipe helps with the choice when failures repeat.
A quote should say who restores the floor, tile or carpet after the work. Restoration is often priced separately, or left to you.
Does slab leak repair need a permit in Los Angeles?
Often yes. The Los Angeles Municipal Code says plumbing work needs a permit from LADBS unless an exemption applies. One exemption covers replacing defective water piping inside a dwelling with piping of equivalent size and quality. A new reroute or a repipe is more likely to need a permit and an inspection. Ask your plumber which applies to your job.
Do not take the permit question lightly. An unpermitted repair can cause trouble when you sell, and an inspection is a second pair of eyes on the new pipe. Ask who pulls the permit, who requests the inspection and whether the fee is in the price.
For concrete work, ask how the contractor will protect the rest of the slab, whether any rebar or post-tension cables are near the leak, and how deep they plan to cut. Post-tension cables in a slab are not something to cut into blind, so the plan should show how the plumber will find them first.
How do I compare slab leak repair companies?
Ask each company the same set of questions, then compare the answers, not just the price. Check the CSLB license at cslb.ca.gov, ask how they will locate the leak, ask which repair methods they offer, and ask for a written scope that separates detection, repair, permit and restoration. A company that only offers one method will recommend it for every leak.
Questions that sort quotes quickly:
- How will you find the leak, and will you give me a written result?
- Is the detection fee credited if I go ahead with the repair?
- Which method do you recommend here, and why not the others?
- Who pulls the permit and who handles the inspection?
- What is included for the floor, tile or carpet afterward?
- What happens if the leak is not where you expect?
California requires a written contract for home improvement jobs over $500 and caps the down payment at $1,000 or 10 percent of the price, whichever is less. If a company wants a large deposit before anything is found, walk away.
We'll arrange a local plumber to visit and give you a written quote through our quote page.
Do slab leak repair companies cover Orange County?
This site is about the City of Los Angeles. Slab leak repair follows the same logic anywhere in Southern California: detect, then choose between a spot repair, a reroute or a repipe. What changes is the permit office. Inside the City of Los Angeles that is LADBS, and other cities and counties have their own building departments and rules.
If your home is outside the City, check which city or county permit office covers the property, and ask any company you are considering to say which permits they pull there. Do not assume a Los Angeles price carries over.
Common questions
How long does a slab leak repair take?
A spot repair is often done in a day or two once the leak is found, with extra time for concrete to cure and floors to be finished. A reroute through walls or the attic can take several days. A repipe takes longer. Permits, inspections and the flooring trade add time on top, so ask for a timeline in the written quote.
What should I ask before I hire someone for slab leak repair?
Start with the CSLB record at cslb.ca.gov. Then ask how the leak will be located, which repair method is proposed and why, who handles the permit, and what restoration is included. Ask what happens if the cause turns out to be a larger pipe problem. Anything over $1,000 or 10 percent as a deposit is above the California cap.
Does someone need to be at the property?
Be home at the start and the finish, and reachable in between. The plumber must get into every room the pipe runs through, and you may need to approve a change once the floor is open. Many people leave the house during concrete cutting, since it is loud and dusty.
Is slab leak detection a separate charge from the repair?
Often, yes. Published guides put leak detection at roughly $150 to $600, and many companies bill it as its own visit. Some credit it toward the repair if you proceed. Ask before the visit so you know. Our leak detection cost guide has the ranges.
Can a slab leak wait until I can afford it?
A leak that you know about gets worse, and the water can rot a subfloor or raise your bill every month. If you cannot repair it at once, shut the water at the main when you are out and ask a plumber what can be done in stages. A large leak is an emergency, so turn off the main right away and call.