Leak Detection & Slab Leak Repair in San Antonio, TX

We use the leak itself. A pressurized line that is leaking makes noise, and a hot line leaking under the slab warms the concrete above it. We first isolate which line is losing pressure, hot or cold, then listen along the slab with acoustic equipment and scan the floor with a thermal camera. Between the two, we can usually mark the leak to within a small area. Only then does anyone open the floor, and only there. In houses where the line runs under finished flooring you do not want disturbed, rerouting the line overhead avoids the slab entirely.

A spot repair fixes one leak. A reroute retires the whole run. In a 1970s house on clay where the copper has already pinholed once, we will usually tell you the second leak is coming, and rerouting the hot line through the attic and down a wall costs less over five years than opening the floor twice. In a newer home with one isolated failure, or where the leak is close to an exterior wall, a spot repair is the sensible answer. We quote both and give you a straight recommendation. The full comparison is on our water line repair page.

Start at the meter. Turn off every fixture and the sprinkler system, then watch the meter for a few minutes; if it moves, you have a leak. Next, shut the valve on top of the water heater. If the meter stops, the leak is on the hot side, which in San Antonio usually means under the slab. If it keeps moving, check toilets by putting food coloring in the tank and waiting ten minutes without flushing. Irrigation systems are the other common culprit here, especially older ones with cracked laterals that only leak while a zone runs. If none of that finds it, the leak is likely underground between the meter and the house, and that is what our equipment is for.

Yes, and the difference is real. Homes on the expansive clay that covers much of the east, south and central parts of the metro see the most foundation movement, and movement is what stresses the pipes cast into a slab. Homes on the limestone north and west of the city, toward Helotes, Boerne and the Hill Country, move less but have thinner soil and rock to dig through when a yard line fails. Age matters as much as location: copper under a slab from the 1960s through 1980s has had decades of hard water and pressure cycles. Keeping the soil around the foundation evenly watered during a drought helps more than most people expect.

It can. Lifting a slab back to level moves the pipes cast into it, and a line that was already brittle or stressed may separate at a joint. That is why we recommend a plumbing pressure test and a sewer camera inspection after any foundation leveling on a San Antonio home, and ideally before, so you know what condition the lines are in. Many foundation companies ask for exactly that. A test after the lift confirms the supply and drain lines survived the move, and if something did give, you catch it while the foundation crew is still involved rather than months later as a wet floor.

Once the leak is marked, the repair has a predictable shape. We shut off the water and open the slab at the marked spot, lifting a square of tile and opening a few inches of concrete, or tunneling in from outside if the line runs near an exterior wall. We dig down to the pipe, cut out the failed section and splice in new pipe with proper fittings, then pressure-test the line at full house pressure before anything is covered. Soil goes back in and is compacted, the concrete is patched flush, and finished flooring is restored after that.

Hot lines fail more often here because Edwards Aquifer scale and heat work on copper together. Slab leak repair in San Antonio is priced in writing before we cut, and our San Antonio plumbers show you the location first.

It comes down to where the leak sits and what is on top of it. A leak within a few feet of an exterior wall can usually be reached by tunneling under the slab from the yard, which leaves your flooring untouched, the usual choice under hardwood or tile you cannot match. A leak under an interior hallway or the middle of a bathroom is often quicker to reach from above, through a small opening in the floor.

A third path skips the slab entirely: abandon that run and reroute a new line through the attic and down a wall. In San Antonio homes on clay where the copper has pinholed before, we often recommend it. You get written prices for each route, and the slab leak repair carries the Home Comfort Guarantee either way.