What is slab leak water damage?
Slab leak water damage is damage from a water line leaking under or inside a home's concrete foundation. Because almost every East Valley house is built slab-on-grade, with no basement or crawl space, supply lines often run beneath the concrete. When one leaks, water soaks up through the slab into flooring, carpet pad, baseboards and the bottom of walls, often for weeks before anyone notices.
Why slab leaks are common here
Three local conditions work against pipes under East Valley slabs:
- Hard water. Minerals in the water and its chemistry slowly corrode copper pipe from the inside, producing pinhole leaks.
- Expansive soil and caliche. Desert soils shift as they wet and dry, putting stress on pipes and on the slab around them.
- Pipe age. Many homes in central Mesa, Tempe and Chandler were built in the 1970s through 1990s with copper under the slab. Early-2000s homes in Gilbert and Queen Creek are now reaching the age where pinholes start.
Hot water lines fail more often than cold, because heat speeds corrosion and causes the pipe to expand and contract.
Signs of a slab leak
Watch for these warning signs:
- A warm spot on the floor, often from a hot water line
- The sound of running water when every fixture is off
- A water bill that jumps without a change in use
- A water meter that keeps moving with all water turned off
- Damp or warped flooring, loose tile or wet carpet with no visible source
- Musty smells along baseboards
- New cracks in tile or the slab
Our guide to slab leak signs explains how to run the water meter test yourself.
How we restore slab leak damage
- Coordinate with your plumber. The leak must be found and repaired or rerouted before drying can finish.
- Map the wet area. Moisture readings on the slab, flooring and walls show how far water spread, which is often several rooms.
- Remove what can't be dried. Carpet pad, laminate and vinyl plank that trap water usually come up. Tile set directly on concrete can often stay.
- Dry the slab and walls. Dehumidifiers, air movers and specialty floor drying systems pull water out of the concrete and the bottom of the drywall. See structural drying for how it's measured.
- Check for mold along baseboards and wall bottoms, and remove it with containment if found.
- Repair. Our water damage repair crew replaces baseboards, drywall and flooring once readings confirm dry.
Slab leak repair vs water damage restoration
Repairing the pipe and repairing the house are two different jobs. The plumber's job ends when the pipe stops leaking, whether through a spot repair in the slab, a reroute or a whole-house repipe. Our job is everything the water touched. If you don't have a plumber, we can recommend one.
Insurance and slab leaks
Slab leak claims are some of the hardest to read in a homeowners policy. Many policies cover the resulting water damage and "tear out" to reach the pipe, but exclude the pipe repair or damage from a leak that ran a long time. We document the moisture spread, photograph every opened area and share the drying log with your adjuster.