Slab Leak Detection & Repair Across Arizona

A slab leak is a leak in a water line that runs under or through the concrete slab beneath your home. Because the line sits out of sight, the leak can run for days or weeks before it shows. Water spreads through soil and concrete, so the damp patch on your floor may sit some distance from the leak itself. Detection comes first: we narrow the leak to one place with listening gear, thermal imaging, pressure testing, and moisture readings, and then we match the repair to what we found.

If your floor feels warm in one place, the meter moves with all water off, or the water bill jumped for no clear reason, you are in the right place. The sections below walk through the whole job: the signs, why Arizona ground and water wear on buried lines, how we locate a leak without opening the slab, the repair options, the steps we follow, and the cities we serve. If you already know you need one repair option, go straight to the service for it: slab leak spot repair, water-line reroute and repiping, commercial leak detection, pre-purchase leak inspection, or slab leak prevention.

Signs You May Have a Slab Leak

A slab leak rarely announces itself with a puddle. It shows up as small changes around the home that are easy to brush off one by one. If two or more show up at the same time, call us for a meter check before any repair work starts.

• A warm spot on the floor. A leak on a hot water line warms the concrete and the flooring above it. A patch that feels warm while the rest feels cool is a classic sign.
• The sound of running water when every tap is off. A faint hiss or trickle with no tap open means water is moving somewhere it should not be.
• A damp or stained patch on flooring. Tile may darken, grout may stay damp, carpet may feel cool and spongy underfoot, and wood may cup or swell.
• A water bill that climbs without a change in use. If use jumps while your habits stay the same, a hidden leak is a likely cause.
• A meter that keeps moving with all water off. Turn off every tap and appliance that uses water, then watch the meter dial. If it still moves, water is leaving the system somewhere hidden.
• Low pressure at a tap. A leak bleeds off pressure before water reaches the tap. If one tap runs weak while others run fine, its line may be losing water under the slab.
• A musty smell near the floor. Water trapped under flooring feeds mold growth in grout, carpet backing, and baseboards. A damp, earthy smell that will not clear points to moisture below.
• New cracks near a damp area. Water softens soil under the slab, and a slab that loses support can shift and crack. A fresh crack beside a damp patch deserves a fast check.

Why Arizona Homes See Slab Leaks

Across Arizona, homes commonly sit on concrete slabs with water lines run beneath them, in direct contact with soil, concrete, and heat. Four local conditions wear on those lines over time. None of this means a leak is your fault. It means a slab leak is a plumbing problem with local causes. The Arizona Department of Water Resources and the official Arizona state website publish the state water and land data behind these conditions.

• Hard water Arizona water runs hard in many areas, carrying dissolved minerals that leave buildup inside lines and wear at joints and bends. That wear can thin a line until a small opening forms and water starts to escape under the slab.
• Expansive clay soil Parts of Arizona sit on clay soil that swells when wet and shrinks as it dries, shifting the ground under a slab and stressing buried lines. A line that flexes again and again can crack at a joint or a bend.
• Long hot summers Long hot summers warm the ground, the slab, and the lines within it, and lines expand and contract as temperatures swing between day and night and between seasons. That steady movement adds wear at fittings and joints.
• Aging copper lines Older homes often carry copper water lines. Water moving through a line over a long stretch wears the inner wall, and hard water adds to that wear. A thin spot can open into a pinhole leak under the slab.

How Detection Works

Detection answers one question: exactly where is the water coming out? We combine five methods so no single reading decides the repair, and together they point to one place. Acoustic listening hears water moving where it should not, thermal imaging sees the warm trail a hot line leaves, pressure testing shows whether the system holds, moisture readings map the damp, and a camera looks inside the lines themselves. No concrete comes up until the methods agree.

1. 1

   Meter check

   All water off, then watch the dial.

2. 2

   Acoustic listening

   Hear water moving where it should not.

3. 3

   Thermal imaging

   See the warm trail a hot line leaves.

4. 4

   Pressure testing

   Find which line loses pressure.

5. 5

   Moisture readings

   Map how far the damp has spread.

1. Acoustic listening

A leak under pressure makes noise as water escapes through a small opening. We place a sensitive listening device on the floor and move it across the rooms where the signs show. The sound grows louder as we near the leak and fades as we move away. A quiet home helps, so we ask that dishwashers, washers, and other noisy appliances stay off during this part of the visit.

2. Thermal imaging

A thermal camera reads surface warmth across the floor and shows it as a color picture. A leak on a hot water line warms the concrete above it, so it shows up as a warm patch. Thermal imaging suits hot lines. Cold lines do not warm the floor the same way, so a cold-line leak calls for the other methods to carry the search.

3. Pressure testing

Pressure testing tells us which line leaks, even when the leak itself stays hidden. We isolate one section of line at a time and watch whether it holds pressure. A section that loses pressure holds the leak, while a section that holds steady is sound.

4. Moisture assessment

A moisture meter reads how much dampness sits in flooring and concrete. We take readings across the rooms where signs show and compare damp zones with dry ones. The pattern maps how far water has spread and points back toward the source.

5. Camera inspection

When a drain line under the slab is the suspect, a small camera travels through the line and shows cracks, breaks, and low spots where water pools. Camera work suits drain lines, not supply lines, since supply lines are too narrow for a camera.

How Repair Works

Once we know where the leak sits, we walk through the repair options that fit your leak. The right fix depends on where the line runs, how many times it has leaked, what sits above it, and what the line looks like overall.

From First Call to Confirmed Fix

Every job follows the same order, from the first call to the final check that the leak is sealed. You describe the signs, we run a meter check and walk the home, we locate the leak with listening gear, thermal imaging, pressure testing, and moisture readings, and then we walk through the repair options that fit what we found. The steps below are that order, and the last step is the one that matters most: we confirm the leak is sealed before we call the job done.

Which Fix Fits Your Leak?

The fix that fits your leak depends on what we find during detection, and we will walk through it with you before any repair work starts. A single leak in a sound line usually takes a spot repair, while a line that has leaked before or tests weak along its length usually takes a reroute. The table below sets the choice out in plain terms: how each fix works, when it fits, and what to expect while the work runs.

Swipe or scroll sideways to see the full table →

Service Areas Across Arizona

We serve homes across Arizona from our base in Tempe. These are the cities we visit most often. See all service areas for the full list. Phoenix is the largest of them, and the City of Phoenix official website carries its water service and city information.

• Phoenix
• Tucson
• Mesa
• Chandler
• Gilbert
• Glendale
• Scottsdale
• Peoria
• Tempe
• Surprise
• Buckeye
• Goodyear
• View all service areas

Frequently Asked Questions

Last updated: November 14, 2026.