What is a slab leak and how do I get it fixed?

If you’ve ever heard water running when no fixtures are on, noticed warm spots on your floor, or found unexplained increases in your water bill, you may be dealing with a slab leak. These leaks can cause major damage if ignored, especially in Phoenix, where many homes are built on concrete slabs.

What Is a Slab Leak?

A slab leak happens when a water pipe beneath your home’s concrete foundation becomes damaged and starts leaking. There are two main types:

• Freshwater slab leaks – leaks in the pressurized water lines.

• Sewer slab leaks – leaks in the drainage pipes under the slab.

Because these pipes are underground, slab leaks are difficult to spot early and often cause damage to floors, foundations, and walls.

Common Signs of a Slab Leak

A slab leak usually starts subtly. Here are the most common warning signs:

1. Unusually high water bills

If your usage hasn’t changed but the bill keeps rising, water may be leaking under the foundation.

2. Warm or damp spots on the floor

A hot water slab leak can heat up portions of the floor, even through tile or carpet.

3. Sound of running water

You may hear water moving even though all faucets and appliances are off.

4. Cracked flooring or foundation

Persistent leaking can lead to shifting or cracking in the slab.

5. Mold, mildew, or musty smells

Moisture trapped beneath the flooring often leads to mold growth.

What Causes a Slab Leak?

In Phoenix and the surrounding areas, slab leaks commonly occur due to:

• Soil shifting and ground movement: Expansive desert soils can shift during extreme heat or monsoon moisture.

• Corroded pipes: Homes with older copper plumbing are more susceptible to corrosion over time.

• Poor installation: Improper pipe placement or inadequate insulation can cause friction and weakening.

• High water pressure: Excessively high pressure puts strain on pipe walls.

How Plumbers Detect Slab Leaks

Modern plumbers use advanced, noninvasive tools to locate slab leaks accurately. These methods include:

1. Electronic Leak Detection

Specialized sensors pick up the sound of escaping water.

2. Infrared Thermal Imaging

Helps identify temperature differences in floors caused by hot water leaks.

3. Pressure Testing

Ensures the plumbing system is holding proper pressure.

4. Camera Inspections

A sewer camera can pinpoint damage or blockages under the slab.

How Plumbers Fix a Slab Leak

After locating the leak, plumbers use one of several repair methods depending on the severity and location of the problem.

1. Spot Repair

If the leak is isolated and accessible, the plumber opens the concrete, repairs or replaces the damaged pipe, and reseals the area. This is best for small, single-location leaks.

2. Rerouting the Line

Instead of opening the slab, the damaged pipe is abandoned, and a new line is run through the walls or ceilings. This is common for older homes with multiple weak spots.

3. Epoxy Pipe Lining

A special epoxy coating is applied inside the pipe to seal leaks. This method is less invasive but depends on the pipe condition.

4. Sewer Pipe Replacement

For sewer slab leaks, plumbers may use trenchless repair options like pipe bursting or relining.

How to Prevent a Slab Leak in the Future

You can reduce the risk of future slab leaks by:

• Installing a water pressure regulator

• Keeping an eye on your water bill

• Scheduling annual plumbing inspections

• Replacing old or corroded plumbing lines

• Softening hard water to reduce pipe wear

If you suspect a slab leak, don’t wait. The longer water flows under your foundation, the more expensive the repairs become.

Call Vertical Plumbing at (480) 577-8720