The idea in one paragraph
Water has to get from the main to the fixture. If the straight path under the floor has failed, nothing says the replacement must follow it. A rerouted line leaves the old pipe where it is, capped off, and carries water up and across through a wall or the attic to the same fixture. The slab above the old pipe is never opened.
Where rerouting makes the most sense
It earns its keep wherever opening the floor would be the expensive or messy part of the job:
- Under a bathtub or shower pan, where reaching the pipe means demolishing tile and the tub itself.
- Beneath a kitchen island, built-in cabinetry or a large stone surface.
- Under floors with a finish that cannot be matched, such as discontinued tile or expensive hardwood.
- Through a section where the slab is thick, reinforced or hard to cut safely.
- When the leak is deep or the soil makes tunneling risky.
It makes less sense when the failing pipe runs to many fixtures, because each branch needs its own new run and the job approaches a small repipe. In that case compare it directly with a partial repipe.
How a reroute is planned and built
- Trace the existing line.The technician locates where the line enters the house, which fixtures it feeds and exactly where it has failed.
- Choose the new path.Usually up through an interior wall, across the attic and down to the fixture, keeping the run as short and as accessible as possible.
- Open small access points.Drywall is cut where the pipe will pass and where it connects. These are patched afterward.
- Install and connect.New pipe is supported, connected and tested before anything is closed up.
- Abandon the old line properly.The leaking section is capped at both ends so it can no longer be pressurized or leave stale water sitting in a dead leg.
- Test and patch.The system is pressure tested and the wall openings are repaired.
Steps three and six are where homeowners should ask questions: where will the access holes be, and who patches them to match the existing wall texture?
What you should know before agreeing to it
What works in its favor
- No concrete demolition, so less dust and no slab patch
- Finish flooring and fixtures can stay in place
- Often faster than a breakout when the pipe is deep
- The new run is accessible if it ever needs service
What to weigh
- The old line is left in place, so the problem section is not removed
- New pipe in an attic needs protection from heat
- Walls need patching and repainting
- If the rest of the line is weak, another leak can follow
That last point is why detection before rerouting matters. A reroute that skips a failing section is only as good as the section it connects to. Ask the technician whether the remaining line was pressure tested and what it showed.
Permits, inspection and records
Changes to a home's water supply generally need a permit and an inspection through the local building department. Ask the contractor who requests it and when the inspection will happen, then keep the paperwork. For a rented property, tell the owner before work starts, since a rerouted line changes the plumbing layout on record.
Rerouting can be combined with other approaches: one stubborn line rerouted, the rest left alone, and a worn run lined with epoxy. If you are weighing these against each other, our decision guide has a short helper to organize the question. Or start from our main page and tell us what you are seeing, or learn more about SlabGuard Pros first.
Questions people ask
Does rerouting mean the old pipe keeps leaking?
Once the old section is capped at both ends it is no longer under pressure, so it cannot leak into the soil. Any water already in the soil and slab should still be dried out.
Will I see the new pipe?
Usually not. New lines run inside walls or in the attic, and access holes are patched. In garages or utility areas, exposed pipe is sometimes acceptable if it is properly supported.
Is rerouting cheaper than breaking the slab?
Sometimes, mostly when the floor above is costly to restore. For a simple, reachable spot, a direct repair can be less expensive, so ask for both numbers.
Can one line be rerouted and the rest left alone?
Yes, that is the common case. It depends on the other lines passing a pressure test.
Last updated October 16, 2026. This page offers general information to help you understand and describe a problem; it is not a diagnosis of your home. Only an on-site inspection can confirm a leak or the right repair.