Slab Leak Detection and Repair for Mount Vernon Homes
A slab leak is a break in a water line that runs under or inside your home’s concrete foundation. Because the pipe is hidden, the leak can run for weeks before you notice it. By then, water may be soaking the soil under your home, damaging flooring, and feeding mold.
CPI Plumbing, Heating, Cooling & Electrical locates and repairs slab leaks for homeowners in Mount Vernon and across Skagit County. Our licensed plumbers pinpoint the leak first, then recommend the repair that fits your pipes, your foundation, and your plans for the home.
Signs You May Have a Slab Leak
Slab leaks rarely announce themselves with a puddle. Watch for these warning signs:
- A water bill that climbs without a change in your water use
- The sound of running water when every fixture is off
- Warm or hot spots on tile, wood, or concrete floors
- Damp carpet, warped flooring, or new cracks in floor tile
- Low water pressure throughout the house
- A musty smell or mildew near baseboards
- A water meter that keeps moving with all water turned off
If you notice one or more of these, shut off any fixtures and check your meter. A moving dial is a strong sign of a hidden leak. Our leak detection team can confirm it.
What to Do If You Suspect a Slab Leak
If you think you have a slab leak, a few quick steps can limit the damage:
- Shut off the main water valve if water is pooling or flooring is getting wet.
- Turn off power or gas to the water heater if the leak may be on the hot side.
- Move rugs and furniture away from damp areas.
- Call a licensed plumber for leak detection.
Avoid chipping into the floor to look for the leak yourself. Without detection equipment, it is easy to open the wrong spot and add to the repair.
How We Find a Slab Leak Without Tearing Up Your Floors
Guessing where a slab leak is costs time and floor space. CPI uses non-invasive slab leak detection to narrow the problem down before any concrete is touched.
- We pressure-test the supply lines to confirm a leak and isolate the hot or cold side.
- We use acoustic listening equipment to hear water escaping beneath the slab.
- We use thermal imaging to trace hot water lines and spot warm areas in the floor.
- We mark the leak location so any access opening stays as small as possible.
Slab Leak Repair Options
Once we know where the leak is and what caused it, we walk you through your repair options in writing before work starts.
Direct spot repair. We open a small section of the slab, repair the damaged pipe, and restore the concrete. This works well for a single leak in a pipe that is otherwise in good shape.
Pipe reroute. We abandon the leaking line under the slab and run a new line through walls, ceilings, or the attic. Rerouting avoids breaking concrete and removes the failed pipe from the system.
Repiping. When pipes are aging or have leaked more than once, more leaks are likely. In that case, whole-home repiping can be the longer-lasting fix.
What Causes Slab Leaks?
Slab leaks usually come from a mix of pipe age, water chemistry, and ground movement. Common causes include:
- Corrosion on older copper or galvanized lines
- Abrasion where pipes rub against concrete, gravel, or other pipes
- Soil shifting from freeze-thaw cycles and wet North Sound winters
- High water pressure that strains joints and fittings
- Poor installation when the home was built
Hard or aggressive water can speed up corrosion over time. A water softener or water filtration system can help protect your pipes after a repair.
Why Mount Vernon Homeowners Choose CPI
- Licensed plumbers who stay current on Washington plumbing codes
- Written quotes before any work begins
- Accurate detection that keeps floor openings small
- Repairs and installations we stand behind
- Local service across Mount Vernon, Burlington, Sedro-Woolley, and Skagit County
We also handle the work that often comes with a slab leak, including water line repair and water heater service when a hot water line is involved.
Schedule Slab Leak Repair in Mount Vernon
The sooner a slab leak is found, the less damage it causes. Call CPI at 360-822-9306 or schedule online to book slab leak detection and repair in Mount Vernon, WA.



