Slab Leak Warning Signs

By the Plano 24 Hour Plumber team · Updated September 2026

Why Slab Leaks Happen Here

Almost every house in this part of Collin County is built on a concrete slab, and the water lines serving it run under or through that slab. The soil beneath is expansive clay: it swells when it takes on water in a wet spring and shrinks back in a dry summer. Everything sitting on it moves a little with each cycle, year after year, and the pipes cast into or buried under the concrete move with it.

Add normal corrosion in older copper, the occasional construction nick on a newer line, and a hard freeze like the one in February 2021 that stressed plumbing across the region, and you have a fairly ordinary local problem rather than a rare disaster. The reason slab leaks get expensive is not usually the pipe. It is how long they run before anyone notices.

The Signs Worth Acting On

A warm patch on the floor is the classic one. Hot water lines lose heat into the slab above them, so a specific area of tile or wood that is noticeably warmer than the floor around it, with no underfloor heating in the house, deserves a second look. Cold line leaks do not do this, which is why they often go unnoticed for longer.

The sound of running water when everything is turned off is another. Stand in a quiet house at night and listen. A faint continuous hiss or trickle with no fixture running is not your imagination.

Then there are the slower signals: a water bill that climbs month after month without a change in how you use water, water pressure that has quietly dropped, damp edges where flooring meets a wall, flooring that lifts or buckles in one area, a persistent musty smell in one room, or new cracks appearing in a floor or a wall. Any one of these alone can have another explanation. Two or three together usually do not.

The One Test You Can Do

The meter test is simple, safe and genuinely useful. Turn off every fixture and appliance that uses water, including the ice maker and any irrigation. Go to the meter box near the curb, lift the lid and note the reading, including the small leak indicator dial if yours has one. Wait an hour without using any water, then read it again.

If the numbers have moved, water is going somewhere. That does not prove the leak is under the slab, but it proves there is one, and it is the single most useful thing you can tell a plumber when you call. If the property has irrigation, run the test again with the irrigation isolated, because a stuck sprinkler valve produces the same result.

What Not to Do

Do not break into the slab or pull up flooring to look. Locating a leak under concrete is done with pressure isolation and acoustic equipment precisely so that the opening, if one is needed, can be small and in the right place. Opening the floor first usually means opening it twice.

It is also worth resisting the urge to ignore it because nothing looks dramatic. Water escaping under a foundation keeps changing the moisture content of the clay that supports the house, and that is the part worth taking seriously well before the bill becomes annoying.

What Happens After It Is Confirmed

Detection comes first: isolating the hot and cold lines to establish which is losing pressure, then tracing the leak to a point on the floor above it. Once it is located, there are usually two or three practical routes. A spot repair reaches the pipe through the slab at that point. A reroute abandons the failed section and runs new pipe through walls or the attic instead. Which is better depends on where the leak sits, what is on the floor above it and whether the line has failed before.

A good plumber will explain both options with prices rather than offering only the one they prefer. Slab leak repair covers the process in detail, and leak detection explains how the search itself works.

Older and Newer Housing Around Plano

West and central Plano houses built from the 1970s through the 1990s have had the longest exposure to this cycle, and their original copper has had decades of soil movement to survive. Newer construction is not exempt, because the soil behaves the same way regardless of when the slab was poured, though the odds are lower. Streets in Murphy and other 2000s suburbs see it too, often on longer yard lines rather than under the house itself.

Arrange an Inspection

If the meter is moving, the floor has a warm spot or the bill has climbed without explanation, call Plano 24 Hour Plumber and say what you have observed. Bringing the meter test result to the call saves time. Read how a service visit works, see burst pipe repair if water is arriving fast rather than slowly, or send the details here and the right visit can be planned.