What Drives the Cost of a Slab Leak Repair (Without Made-Up Numbers)

"How much do you charge for leak detection?" and "I was looking to get a price" are among the most common things callers say. Fair questions. This site won't put a number on them, because any figure here would be a guess and the plumbing companies set their own prices. What it can do is explain what makes one slab leak job cost more than another, so the price you hear makes sense.

Finding the leak

• How loud the leak is. A hot-line leak that hisses under a kitchen is found faster than a quiet cold-line drip under carpet.
• Hot or cold side. Hot lines show on thermal imaging; cold lines rely more on listening and pressure tests.
• Flooring. Thick tile on a mortar bed muffles sound. Carpet and pad hide heat.
• How the system is laid out. A house with a manifold or separate valves can be split into sections quickly.
• More than one leak. Two leaks at once take longer to separate.

Ask whether the detection fee goes toward the repair. Some companies credit it.

The repair method

The biggest swing comes from which repair fits the house. The home page compares them in a table, but briefly:

• Spot repair through the slab: cost depends on what has to come up (tile, wood, carpet), how deep the pipe is, and patching the concrete and floor.
• Reroute: cost depends on line length, attic access, how many fixtures the branch feeds and how many wall openings need patching.
• Whole-house repipe: cost depends on the number of fixtures, material (PEX or copper), one or two stories and drywall work.

Things people forget to ask about

1. Floor and drywall patching. Is it included, or does another trade handle it?
2. Permits. Reroutes and repipes commonly need one. Is the permit fee in the price?
3. Concrete patching. Who patches the slab after a spot repair?
4. Water damage cleanup. That's usually a separate company and a separate bill.
5. Access. Built-in cabinets, an appliance on top of the leak, or a tight attic can add time.

Factors specific to older Westminster-area homes

Houses built in the decades after Westminster's 1957 incorporation commonly have copper lines under the slab. If one branch has failed, the plumber may raise whether more will follow, and that changes the math between a single spot repair now and a reroute or repipe. In Fountain Valley, two-story homes can make a reroute longer because lines run through walls instead of straight down from the attic.

What to ask before anyone comes out

• How is detection billed, and is it credited toward the repair?
• Will I get the repair options in writing after the leak is found?
• Is patching (floor, drywall, concrete) part of the job?
• Who pulls the permit?
• What is the California contractor license number? (Check it at cslb.ca.gov.)

Insurance can change what you pay. Slab leaks and homeowners insurance explains how policies often split the costs.