Slab Leak Detection

A slab leak is a water line leaking under a concrete floor: a garage slab, a basement, a slab-on-grade home, a commercial building's lower level. The signs are a warm or damp spot on the floor, water seeping up at a crack or a wall base, a persistent musty smell, a water bill that climbs, or in a commercial building a hallway that is always wet with no plumbing fixture nearby. Because the pipe is under concrete, guessing is expensive. Every exploratory hole is a saw cut and a jackhammer.

We locate slab leaks acoustically. The ground microphone works through concrete, and with the line under pressure the sound of the leak transmits well through the slab. We trace the line's route first where possible, listen along it, and pinpoint the leak so that one section of slab gets opened rather than three. On commercial lower levels we set cones and work lights, mark the wet zone, and keep the rest of the floor usable.

Once the leak is pinpointed, we break out the slab over it with a demolition hammer, expose the line, repair or re-route the section, test, backfill and patch the concrete. Where a slab line has failed more than once, re-routing the supply above the slab or through a new buried line outside the building is often the better long-term answer, and we'll lay out that option plainly.

When you need slab leak detection

• A damp, warm or discolored spot on a concrete floor
• Water seeping up at a crack or at the base of a wall
• A musty smell in a basement or lower level with no visible source
• A water bill that climbs with no exterior wet spot
• A commercial hallway or utility room that is persistently wet
• Low pressure combined with any of the above

How the job goes

1. Confirm the loss. Meter or gauge test with the building's fixtures closed to confirm the line is losing water.
2. Trace the line. Where the line's route under the slab can be traced, we trace it; otherwise we work from the known fixture and supply locations.
3. Listen through the slab. The acoustic ground microphone picks up the leak through concrete. We work the route and pinpoint the loudest, most consistent signal.
4. Open the slab. A saw cut and demolition hammer over the marked spot only. Cones, lights and dust control on commercial sites.
5. Repair or re-route. Repair the exposed section, or re-route the supply if the slab line is at the end of its life.
6. Backfill and patch. Compacted backfill and a concrete patch, and the area cleaned and reopened.

Equipment and materials

• Acoustic ground microphone
• Pipe locator
• Concrete saw and demolition hammer
• Repair fittings for copper, PEX and poly
• Concrete patch materials

What shapes the scope

Every property is different, and these are the things that decide whether a job is a quick morning or a full day. We'll tell you which it is before we start.

• Whether the line's route under the slab is known
• Slab thickness and whether it is reinforced
• Access and working hours on a commercial site
• Whether a repair or a re-route makes more sense