Slab leak repair cost

A slab leak costs $1,500 to $6,000 to repair, typically around $3,000. It is a pipe failure under the concrete floor of the house, and it is expensive because the concrete is in the way, not because the pipe is hard to fix.

Three methods exist and they cost very differently. Which one is right depends on the age of the plumbing and how many leaks you have had.

What it costs

Reinstatement is the row people forget. Breaking a hole through a slab in a tiled kitchen means matching tile that may no longer be made.

The three ways to fix it

Spot repair. Jackhammer through the slab at the located point, cut out the failed section, splice in new pipe, backfill, repour. Cheapest when the leak is genuinely isolated and the flooring above is replaceable. It is the wrong choice if the pipe failed because the whole run is failing.

Reroute. Abandon the section under the slab and run a new line through the attic or the walls to the same fixtures. Costs about the same as a spot repair, does not touch the floor, and is often better value because the abandoned pipe cannot fail again. The trade-off is exposed pipe in a garage or a soffit, and pipe in an attic that must be insulated against freezing.

Repipe. Abandon the slab lines entirely and run the whole house new. This is the answer to a second or third leak, and it is not much more than two spot repairs.

When it is a repipe rather than a repair

• This is the second slab leak. The first one is bad luck; the second is a pattern, and the pipe under the rest of the floor is the same age and in the same soil.
• The pipe is copper in aggressive soil or water. Pinhole corrosion arrives in clusters.
• The house has polybutylene. Repipe, and stop thinking about it.
• The leak is on the hot side and the house is over about 30 years old. Hot lines fail first because heat accelerates everything.

The signs, and how early you can catch it

The earlier one is found the cheaper it is, because the water is eroding soil under your foundation the whole time.

• A warm or hot patch on the floor, most often in a hallway or a kitchen
• The sound of running water with everything turned off
• A water bill that stepped up and stayed up
• Damp or discolored flooring, or carpet that never quite dries
• Cracks appearing in the slab, tile or drywall
• A musty smell with no visible source

Confirm before you panic: shut every fixture, read the meter, wait two hours, read again. Movement means water is leaving the system somewhere.

Frequently asked questions

Will homeowners insurance cover a slab leak?

Most policies cover the cost of accessing the leak, breaking and repairing the concrete, and the resulting water damage, but not the pipe itself. That split surprises people and it is worth reading before the plumber arrives, because the access is most of the money.

Can I ignore a small slab leak?

No. It is running continuously under the foundation, washing out the soil the slab bears on. Foundation movement costs an order of magnitude more than the plumbing does.

Is epoxy lining a real solution?

For a whole system with widespread pinholes it can be, and it avoids opening floors. It is not a fix for a single failed section, it needs a contractor who does it routinely, and it is difficult to undo if it goes wrong. Get two opinions before committing.

How long does the repair take?

A spot repair is one to three days including the concrete cure. A reroute is one to three days. A repipe is three to five. Flooring reinstatement is separate and often longer than the plumbing.

Should I be there for the leak detection?

Yes, if you can. You want to see the mark on the floor and hear which line it is, because that is the conversation that decides between a $2,000 repair and a $9,000 one.