Slab leak signs in a Florida home: how to tell, and what it costs to fix

A warm spot on the floor (a hot-water line is leaking under it); the sound of running water when every fixture is off; a water heater that cycles constantly or hot water that runs out early; a water bill that has climbed with no visible cause; damp or lifting flooring, a musty smell, or mildew at the base of a wall; hairline cracks in tile or slab; and, outdoors, a lush or wet patch beside the foundation. The EPA's two-hour meter test — read the meter, use no water for two hours, read it again — is the first check, and the water-bill guide walks through isolating the house from the yard.

Slab-on-grade construction puts the supply lines in or under the concrete. Copper laid directly in the slab corrodes where it touches the concrete or where the soil chemistry is aggressive, and it wears through at bends where water rushes; the 1978–1995 polybutylene lines fail from the inside as chlorinated water degrades the plastic. Shifting soil and the slab's own settling stress the pipe at every point it is held rigid. None of that is visible until water finds a way up.

Locating comes first — pressure testing the hot and cold sides separately, then listening with acoustic equipment and, where needed, tracing the line — so that whatever is opened is opened once. Then: a spot repair through the slab where the leak is single and the rest of the piping is sound; a reroute of that one line overhead through the attic and walls, which avoids breaking the slab and is often the better value; or a whole-house repipe where the piping is copper of that era or polybutylene, because the next leak is a matter of time.

A repipe in PEX runs $3,500–$8,000 for a typical Manatee County home and comes with drywall patches to close, but it ends the question. Rosco Plumbing quotes all three on the same visit so the decision is made on numbers, and puts the camera or acoustic findings in writing for an insurance claim where the damage is covered.