9 Signs of a Slab Leak in a Florida Home

1. The Water Meter Moves With Everything Off

This is the sign that comes first and the one that can be tested in minutes. Turn off every fixture, appliance and the irrigation, then watch the small leak indicator on the meter. If it creeps along, water is escaping. Close the house shut-off: if the meter stops, the leak is inside the house, and if you can't find a dripping fixture or running toilet, the slab is a prime suspect. Our water meter leak test guide walks through it step by step.

2. The Water Bill Jumps Without a Reason

Water bills in Plant City naturally climb in the dry spring months when lawns need more irrigation, so compare the same months year over year. A bill that rises when your habits haven't changed, or one that keeps rising month after month, points to a leak running around the clock. Under-slab leaks rarely stop on their own; they tend to grow as the water erodes the soil and the pipe around the hole.

3. A Warm or Hot Spot on the Floor

Walk barefoot across tile or bare concrete. A patch that feels noticeably warmer than the rest, especially in a spot with no sun on it, often means a hot-water line is leaking under the slab. Pets sometimes find these spots first and choose to lie on them. Because the heat spreads through concrete, the warm area isn't always directly over the break, which is why infrared thermal imaging is used to map the heat pattern before pinpointing.

4. Running Water When Nothing Is On

In a quiet house at night, listen at floor level near the kitchen, bathrooms and water heater. A faint hiss or trickle with every fixture off can be water escaping under pressure through the slab. Pressurized supply lines are louder than drain lines, and the sound often carries through the concrete to places away from the leak itself.

5. Damp Carpet, Warped Wood or Lifting Tile

Water from an under-slab leak follows the path of least resistance, wicking up through the concrete and into flooring. Carpet padding that stays damp, laminate or wood that cups or swells, and tile that sounds hollow or loosens can all follow. The damage might show up along a wall or in a closet some distance from the pipe.

6. New Cracks in Tile, Walls or the Slab

Every slab has hairline shrinkage cracks, and Florida homes settle. What matters is change: new cracks that appear and grow, especially alongside other signs. A leak washing out the sandy soil under a slab can cause localized settling. Cracking alone doesn't prove a leak, but cracking plus a moving meter is worth a call.

7. Musty Smells or Mildew Near the Floor

A slow under-slab leak keeps the base of walls and the underside of flooring damp. In Plant City's humid climate, that turns into a musty smell, mildew on baseboards or around the bottom of drywall, or a persistent humid feel in one room even with the AC running well.

8. The Water Heater Runs More Than It Should

If a hot-water line is leaking, the water heater keeps refilling and reheating water that's escaping under the floor. A tank that seems to cycle constantly, a gas burner that fires often with no hot water in use, or a jump in the electric bill alongside the water bill all fit a hot-side slab leak. Check the heater itself first: our water heater leak page covers leaks at the tank.

9. Lower Water Pressure Throughout the House

A large leak diverts water before it reaches your fixtures, so showers feel weaker and faucets don't flow like they used to. Pressure can also drop for other reasons, like scaled aerators or a failing pressure regulator, so look at pressure together with the other signs.

What to Do When You Spot the Signs

Start with the meter test, since it confirms or rules out an active leak quickly. If the meter moves with the house valve open and stops when it's closed, and you've ruled out toilets and fixtures, the next step is professional slab leak detection. The provider isolates hot and cold lines with a pressure test, then pinpoints the break with acoustic listening, thermal imaging or tracer gas, so any opening in the floor is small and in the right place.

Frequently Asked Questions