Signs include a water meter that moves with everything off, a wet or warm spot in the floor, flooring that lifts or stains, and a bill that climbs without explanation. Repair options are to open the slab at the break or to abandon the buried line and run new piping elsewhere. Locating the leak comes first.
What are the signs?
- The meter moves with every water use off. EPA's commercial guidance says to read the meter when all uses are off, then read it again an hour later. A significant change indicates a leak somewhere in the distribution system or the building.
- A wet or discolored spot in the floor that returns after you dry it, or flooring that lifts, stains or sounds hollow.
- Water bills that rise without a change in business. EPA recommends comparing monthly bills to the previous month and the same month the year before, allowing for seasonal use.
- Hot spots in the floor where a hot water line leaks. A warm spot in the floor is a classic clue, and the signs page lists more.
- Unexpected water noise or reduced pressure in one area.
Not every wet floor is a water supply leak. A drain or sewer line below the slab can leak too, and that has different signs.
What are the repair options?
| Option | What it means | What to weigh |
|---|---|---|
| Spot repair | Open the slab over the leak and repair the pipe | Smallest repair area, but the floor must be reopened and patched |
| Reroute | Abandon the buried pipe and run new piping through walls or ceiling | Avoids cutting the slab, but means opening walls or ceiling |
Which is right depends on where the pipe runs, what floor finish sits above it, how many leaks the line has had, and what disrupts the business least. A pipe that has leaked once under a slab may leak again, so a plumber will often check the rest of the line. How slab repairs work goes deeper.
What comes before any cutting?
Location. A plumber pinpoints the leak using the meter test and non-invasive methods so the slab is opened in the right place. Ask what the quote covers, including floor and finish restoration.
Phoenix Water Services draws the line at the meter: leaks on the private side belong to the property owner. And once water is stopped, EPA says to respond to water damage within 24 to 48 hours to avoid mold growth.