What is a Slab Leak?
A slab leak occurs when water or sewer pipes buried under a concrete foundation develop leaks. These leaks can cause significant damage if not detected early, including foundation erosion, structural damage, mold growth, and skyrocketing water bills. Professional slab leak detection locates the precise leak location without breaking the entire slab.
Common Causes of Slab Leaks
- Corrosion: Older copper pipes corrode from water chemistry and soil conditions
- Ground Shifting: Soil movement and settling stresses pipes under the slab
- Abrasion: Pipes rubbing against concrete or gravel wear through over time
- High Water Pressure: Excessive pressure weakens pipe joints and connections
- Poor Installation: Kinked pipes or inadequate support during construction
Warning Signs of Slab Leaks
Sound of Running Water
Hearing water running under floors when all fixtures are off is the classic sign of a slab leak.
Warm Spots on Floors
Hot water slab leaks create warm areas on tile or concrete floors, often detectable by thermal imaging.
High Water Bills
Unexplained increases in water usage indicate a significant leak. A slab leak can waste hundreds of gallons daily.
Foundation Cracks
Slab leaks erode soil under foundations, causing cracks, settlement, and structural damage requiring costly repairs.
Low Water Pressure
Reduced pressure throughout the house can indicate a major slab leak diverting water underground.
Professional Slab Leak Detection Methods
Acoustic Leak Detection
The primary method for locating slab leaks. Sensitive ground microphones and electronic amplification make the leak audible through concrete. Pressurizing the system with air or CO₂ increases the leak's volume and pitch for precise pinpointing.
- Ground mics detect leak sound through slab
- Air/CO₂ pressurization amplifies leak noise
- Non-invasive method saves demolition costs
Thermal Imaging
Infrared cameras detect temperature differences caused by hot water leaks under slabs. Especially effective for locating hot water slab leaks before using invasive methods.
Electronic Line Tracing
Locates pipe routes under slabs so acoustic sensors can be placed along the correct path. Essential before spending time listening for leaks.
Pressure Testing
Confirms the presence of leaks and isolates leaking sections before excavation. Separates supply line leaks from drain line issues.
Slab Leak Repair Options
Once located, slab leaks can be repaired through several methods:
- Spot Repair: Breaking through the slab at the leak location and repairing the pipe segment
- Epoxy Pipe Lining: Coating the inside of pipes to seal small leaks without excavation
- Rerouting: Running new pipes through walls or attic spaces to bypass the leaking under-slab section
- Complete Repiping: Replacing all under-slab plumbing when multiple leaks exist or corrosion is widespread
Learn Professional Slab Leak Detection
LeakCraft Pro's slab leak training provides step-by-step workflows for detecting, diagnosing, and documenting slab leaks. Learn acoustic detection techniques, equipment selection, and professional reporting for insurance claims.