A slab leak is a break in a water line that runs beneath your home's concrete foundation. Because the pipe is buried under inches of concrete and soil, the leak never shows itself directly — instead it sends up clues. Catching those clues early is the difference between a contained repair and months of water damage, and in Summerville's many slab-on-grade homes, it's one of the most valuable skills a homeowner can have.
1. Warm spots on the floor
The classic slab-leak tell. A hot-water line leaking under the slab warms the concrete above it, so one patch of tile or laminate feels noticeably warmer than the floor around it. Run your bare feet across suspect rooms — a distinct warm zone that doesn't fade is worth investigating, not ignoring.
2. A water bill that climbs for no reason
When usage habits haven't changed but the bill keeps rising across billing cycles, water is escaping somewhere in the system. Summerville CPW customers should compare the gallon usage line rather than just the dollar amount, since rates and fees can shift while the real story sits in the consumption figure.
3. Sounds of running water with everything off
Stand quietly in the room with the warm spot or the suspect area. If you hear a faint hiss, trickle, or rushing sound while every fixture is off, a pressurized line is likely discharging under the slab. Note where the sound is loudest — that detail helps a technician narrow the search.
4. Low water pressure
A leak diverts pressure away from your fixtures. If showers and faucets have gradually lost force and the change isn't explained by a supply-side issue affecting the whole street, a supply line beneath the foundation is a strong suspect.
5. Damp spots, cracks, or buckling floors
Water under a slab eventually migrates. It can push up through tiny cracks in the concrete, dampen flooring from below, or cause laminate and wood floors to cup and buckle. New cracks in the slab edge or in the foundation stem wall deserve the same suspicion.
6. Musty odors that won't leave
Trapped moisture breeds mildew. A persistent earthy or musty smell in one room — especially near the floor — can be the first thing noticed in homes where the visible signs haven't surfaced yet. In the Lowcountry's humid climate, don't dismiss it as ordinary dampness.
7. The water heater runs constantly
A hot-water slab leak forces the heater to replace lost hot water around the clock. If the unit cycles far more than it used to, or the energy bill jumps alongside the water bill, the two problems may share one underground cause.
What causes slab leaks
Most slab leaks trace back to a few familiar culprits. Copper and older supply lines corrode from water chemistry and soil contact. Pipes can chafe against concrete or rebar as they expand and contract with temperature swings. Shifting soil after heavy Lowcountry rains puts stress on buried lines, and in some homes the original installation simply left a line vulnerable at a bend or joint. None of these are the homeowner's fault — they're the predictable wear of plumbing under a slab.
Slab leaks vs. other hidden leaks
Not every hidden leak is a slab leak, and the distinction matters because each type gets a different search. Wall and ceiling leaks announce themselves with stains and peeling paint at eye level. Fixture leaks — under sinks, behind toilets, around showers — stay local to the bathroom or kitchen. Slab leaks are the ones that stay invisible longest: no stain, no puddle, just the indirect clues above. When symptoms cluster low — warm floors, sounds near the ground, pressure loss across the whole house — the search goes downward, under the concrete. When they cluster around one fixture or one wall, the search stays at living level. Sorting this out before instruments come out saves everyone time.
What to do when you spot the signs
Start with a simple meter check: with all water use stopped, watch the meter for movement over an hour or two. If it advances, water is leaving the system somewhere. Resist the urge to let anyone break concrete on a guess — professional slab leak detection uses acoustic listening and thermal imaging to pinpoint the break first, so any repair opens one precise spot. Call +1 843-936-8115 — open 24 hours.