Leak Detection Guide
If part of your floor feels noticeably warmer than the rest, especially over a hot water line, that's one of the more specific slab leak signs there is — it usually means hot water is escaping under the concrete and heating the slab above it. A damp or discolored patch on carpet or tile, even without warmth, points to a cold water line leak in the same way.
A slab leak is a continuous, pressurized leak, so it doesn't show up as a one-time spike — it shows up as a new, sustained increase in your average usage. If your bill has been meaningfully higher for two billing cycles in a row and nothing about your household's water use has changed, that pattern matters more than the size of any single bill.
Turn off every faucet, appliance, and irrigation line, then listen near the floor in a quiet room. A hissing or running sound with nothing actually running is one of the more reliable signs, since it's very hard to explain any other way.
Water escaping under a slab can erode the soil supporting it, causing slight shifting that shows up as new cracks in tile, baseboards, or drywall — particularly cracks that appear suddenly rather than the hairline settling cracks most homes develop gradually over years.
A musty smell in a room with no visible water damage, no recent spill, and no humidity issue is worth investigating, since moisture trapped under flooring can support mold growth long before it becomes visible from above.
If one specific fixture has noticeably weaker pressure than the rest of the house, and it isn't a fixture-specific clog, it can mean a slab leak on that line is diverting pressure before the water reaches the fixture.
Acoustic leak detection equipment listens for the specific frequency signature pressurized water makes escaping through a small opening — a steady hiss rather than a knock or drip. It's a genuinely different sound than pipes settling or normal household noise, which is why trained listening equipment finds leaks a homeowner's ear usually can't.
