A slab leak is a supply pipe leaking under or inside concrete. The water has nowhere to go but up, so it shows first as a warm patch, a musty smell or flooring that lifts. A plumber finds and stops the leak, and the restoration crew then dries everything the water soaked.
Signs that point under the floor
These clues often appear before any water is visible:
- A warm spot on the floor that is not near a vent or sunny window.
- Carpet that stays damp or smells musty after the surface is dried.
- Baseboards that swell or paint that bubbles low on the wall.
- Tile or hardwood that lifts, cups or sounds hollow in one area.
- A water meter that keeps moving when every fixture is off.
Why age matters in San Dimas
The median San Dimas home was built in 1976, and the 1970s is the city's biggest building decade with 3,983 homes. About 7,826 of 12,370 homes predate 1980. Age alone does not prove a leak, but plumbing that has served for decades is a fair reason to check the meter after any unexplained dampness.
How the drying works over concrete
Concrete holds water far longer than drywall does. Once the wet flooring is lifted, readings are taken on the slab and the lower walls, and refrigerant dehumidifiers run with air movers to draw moisture upward. Dense or sealed slabs can need desiccant units, and drying continues until the slab reads dry so new flooring does not trap what is left. Tile and hardwood laid over the slab are the hardest to save (see hardwood floor water damage), while carpet and pad are often lifted so the concrete can release its water. The equipment side is described under structural drying.
Photos of the exposed pipe, readings across the slab and a floor plan marked with wet zones go into the file, so the plumber's repair and the drying records tell one story.