Slab leak repair: the three approaches
There is rarely one correct repair. There are three, and which one fits depends on the age of the plumbing and whether this is the first failure or the third.
Signs to look for
- A leak has been located and you are choosing how to fix it
- This is not the first slab leak in the house
- You are weighing a quick repair against a permanent solution
Several of these signs also fit something above the slab, and one free check separates them better than a list can. The slab leak check asks what you are seeing, what the water meter does with everything shut off, and where the sign sits.
- 1 AC condensate. The pan overflows up in the attic and finds the ceiling below it.
- 2 The ceiling stain. It marks where the water arrived, not where it started out.
- 3 A burst supply line. Pressurized pipe inside a wall, running until the main is shut.
- 4 The water heater. Often in the garage, and its failure runs toward the house, not away from it.
- 5 A slab leak. It travels sideways under the concrete and surfaces long after it began.
Spot repair
The floor is opened directly above the failure, the concrete is cut, and the damaged section of pipe is replaced. It is the least expensive option and the most disruptive to the room it happens in.
It makes sense when the plumbing is otherwise in good condition and this is a first failure. It makes less sense when the same line has failed before, because the conditions that caused it apply to the rest of the run too.
Rerouting
The failed line is abandoned in place and a new one is run above the slab, through walls and attic instead of under concrete. The floor stays intact; drywall gets opened instead.
This is common in Orange County precisely because opening a slab under tile or hardwood is so costly.
Repiping
The whole supply system is replaced. It is the largest job and the one that ends the problem rather than managing it. On a house that has had multiple slab leaks, it is often cheaper over a few years than repairing them one at a time.
Fixing the source is only half of it
Whichever approach is chosen, the plumbing repair and the drying are separate jobs, usually done by different trades. The water that got out before the repair is still in the structure afterward.