A slab leak is a leak in the water supply or drain pipes that run under your home’s concrete slab foundation. Because those pipes are buried in the slab, the leak stays hidden until you notice one or more of these warning signs. Catching a slab leak early can limit water damage, mold, structural damage, and repair cost. Here’s what to look for—and what to do next.
Unexplained high water bill
Your water usage hasn’t changed but the bill has gone up. A slab leak can waste hundreds of gallons a day, so the water meter and your bill are often the first clue.
Water meter moving when nothing is on
Turn off all fixtures and appliances that use water, then check your water meter. If the small dial or leak indicator is still moving, there’s an active leak somewhere—possibly under the slab.
Warm or hot spots on the floor
If a hot water line is leaking under the slab, the floor above can feel warm or hot in spots. This is a strong sign of a slab leak in the hot side.
Sound of running water when nothing is on
Water escaping from a pipe under the floor can sound like running water, dripping, or hissing. If you hear it with all fixtures off, the leak may be under the slab or in a wall.
Damp or warping flooring
Moisture from a slab leak can seep up through the slab and into flooring. You might see damp spots, warping, or loosening tile or laminate.
Mold, mildew, or musty smell
Trapped moisture under the slab or in the room can lead to mold growth and a persistent musty odor. In Florida’s humidity, mold can develop quickly once moisture is present.
Low water pressure
A significant leak under the slab can reduce water pressure to fixtures because water is being lost before it reaches them.
Cracks in flooring or foundation
In severe or long-standing cases, moisture and soil movement can contribute to cracks in the floor or foundation. Not every crack means a slab leak, but combined with other signs it’s worth having a professional check.
You can’t see the pipe under the slab, so confirmation usually requires leak detection by a licensed plumber. We use acoustic sensors to hear water escaping through the concrete, thermal imaging to see temperature changes from the leak, water meter and pressure tests to confirm and isolate the leak, and sometimes video inspection of the plumbing. That lets us pinpoint the leak so we can recommend the right repair—epoxy lining, pipe rerouting, or targeted slab access—without tearing up your whole floor on a guess.
Slab leaks are common in Florida because many homes are built on slab foundations with copper or galvanized pipe running through or under the slab. Over time, corrosion from hard water, mineral buildup, sandy soil and shifting, tree roots, or foundation settlement can cause pinhole leaks or larger breaks. The pipe is out of sight, so the leak can run for a while before you notice the signs above. Leak detection and slab leak repair sooner rather than later protect your home and your wallet.
1. Don’t ignore them — The longer the leak runs, the worse the water damage, mold, and repair cost can be.
2. Schedule leak detection — A licensed plumber with acoustic and thermal equipment can locate the leak without digging first.
3. Get a repair estimate — Once we know where the leak is, we’ll recommend the best repair (epoxy, rerouting, or targeted repair) and give you an estimate or upfront pricing before we proceed.
At Leak Repair Florida we specialize in slab leak detection and slab leak repair across Florida. We’re based in Orlando at 426 W Robinson St, Orlando, FL 32801 and serve Central Florida, Tampa Bay, South Florida, Space Coast, and Northeast Florida.
Contact us for slab leak detection and repair.
Slab Leak Repair · Water Leak Detection · Leak Repair Florida