A slab leak is a leak in a water or drain line that runs under or inside a home's concrete slab foundation. Because it's hidden under the floor, it can run for a long time before it's noticed.

What are the signs of a slab leak?

Common signs include a water bill that jumps for no reason, the sound of running water when everything is off, warm or damp spots on the floor, cracks in flooring or baseboards, mildew smells, and the water meter moving when no water is being used.

How are slab leaks found?

Plumbers use leak detection methods like pressure testing individual lines and acoustic listening equipment to pinpoint the leak's location, so only a small area of floor needs to be opened, or the line can be rerouted around the slab.

Slab Leak Signs Every Homeowner Should Know

Homes built on a concrete slab have water lines running underneath or through the foundation. When one of those lines leaks, the water has nowhere visible to go, so slab leaks can run for weeks before anyone notices.

Warning signs

Your water bill jumps and your water use hasn't changed.
You hear running water when every faucet and appliance is off.
A spot on the floor feels warm (a hot water line leak) or damp.
Cracks appear in tile, flooring or baseboards.
Musty or mildew smells, or mold along the bottom of walls.
Low water pressure throughout the house.
The water heater runs constantly.

The water meter test

Turn off every faucet, appliance, irrigation system and ice maker.
Find your water meter and note the reading, or watch the leak indicator (often a small triangle or dial).
Wait an hour without using any water, then check again.

If the meter moved, water is leaking somewhere. It could be a toilet or outdoor line, but if you can't find a visible source, a hidden or slab leak is a real possibility. More signs: 5 signs you have a hidden water leak.

What causes slab leaks

Corrosion of older copper or metal lines.
Pipes rubbing against concrete or gravel as they expand and contract.
Soil shifting under the foundation.
High water pressure stressing the lines.

How it's fixed

The first step is pinpointing the leak with professional leak detection, so only a small section of floor is opened instead of guessing. Depending on the location and the condition of the pipe, the fix may be a spot repair through the slab or rerouting the line through the walls or attic.

Think you have a slab leak in Greer, Simpsonville, Mauldin or anywhere in the Upstate? call us at 864-365-8900 — we answer 24/7. The sooner it's found, the less damage it does.

Frequently Asked Questions

What is a slab leak?: A slab leak is a leak in a water or drain line that runs under or inside a home's concrete slab foundation. Because it's hidden under the floor, it can run for a long time before it's noticed.
What are the signs of a slab leak?: Common signs include a water bill that jumps for no reason, the sound of running water when everything is off, warm or damp spots on the floor, cracks in flooring or baseboards, mildew smells, and the water meter moving when no water is being used.
How are slab leaks found?: Plumbers use leak detection methods like pressure testing individual lines and acoustic listening equipment to pinpoint the leak's location, so only a small area of floor needs to be opened, or the line can be rerouted around the slab.

Need help with leak detection & burst pipe repair? We serve Greer and the Upstate, 24/7.

Call 864-365-8900

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