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Slab Leak Repair

A slab leak is a leaking water pipe under a concrete floor. Common signs are a higher water bill, warm spots on the floor and the sound of running water. Leak detection costs about $150–$600, and slab leak repair averages around $2,280, with most homeowners paying $630–$4,400.

Fix this weekDIY: Pro only1–2 days (professional)Pro: $630–$4,400

Last reviewed September 2026

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Check 1 of 11Testing: Slab leak
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Does the water meter move with all taps off?

Turn off every tap and appliance and watch the meter. If it moves, water is escaping.

Signs it's this problem

  • Water bill rising with no change in use
  • Warm or hot spots on the floor (hot water line)
  • Sound of running water when everything is off
  • Damp carpet, warped flooring or new cracks in the slab

Why it happens

Water lines run under many slab-foundation homes. Corrosion, abrasion against concrete, poor installation and ground movement can wear pinholes or cracks, and the leak stays hidden until water or heat shows up above it.

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How to fix it, step by step

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Safety: Don't break concrete yourself; slabs can hide electrical, gas and post-tension cables.

Slab Leak Repair cost

US national ranges for professional work, including labor and materials
JobTypical cost
Slab leak repair including detection (average about $2,280)$630–$4,400
Professional leak detection$150–$600
Reroute the water line$1,500–$4,500

Got a quote? Check if it's fair

Typical professional price for this job: $630–$4,400

Common questions

How do I know if I have a slab leak?

The water meter test is the easiest check: with every fixture off, the meter shouldn't move. Warm floor spots, running water sounds and rising bills add to the evidence.

Is it better to repair or reroute a slab leak?

Spot repair is cheaper for a single leak in otherwise good pipe. Rerouting avoids breaking the floor and is often preferred when pipes are old or leaks have happened before.