Slab Leak Repair in Washington, DC

Where buried leaks hide in District homes

Many DC houses and rowhouses have basements, and the water service often enters below grade and travels under or along the basement floor before rising to the first fixtures. Kitchens and baths added at basement level, English basement apartments and rear additions on slabs all put pipe under concrete. With a median year built of 1957, much of the city's housing has older copper or galvanized steel in those buried runs, and either can wear through with age.

Signs that point to a slab leak

• A damp or darkened patch on a basement floor that returns after you dry it
• Warm spots on the floor above a hot water line
• The water heater cycling when nobody is using hot water
• Hissing or trickling with every faucet closed
• A DC Water bill that climbs while household use stays the same

A quick meter test

Close every faucet and stop appliances that use water. Read the meter, wait an hour without running anything, then read it again. A change means water is going somewhere. If you can close the main shutoff and the movement stops, the leak is inside the house. If it continues, look at the service line between the meter and the house instead, which is covered on the water line repair page.

How a plumber finds it

The usual steps are isolating hot and cold lines and pressure-testing each one, then using acoustic listening gear on the floor to hear where water escapes. Thermal imaging helps trace hot lines. The tighter the locate, the less concrete has to be cut.

Repair choices

Cost factors

Locating time, how much concrete and finished flooring sit over the leak, the repair route, and any drying or finish work afterward drive the price. Adding or replacing piping can require a DC Department of Buildings plumbing permit, which only a contractor holding a DC plumbing license can pull, so ask who handles it.