A supply line fails inside or beneath the concrete and the floor becomes the only witness. Here the next question is not where to cut. It is what the slab is carrying, and what the clay beneath it does once it gets wet.
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Six boxes, about thirty seconds. You pick when to be called back, and that is when the phone rings.
Or call (619) 603-0192The loud version is a hot-water failure: a patch or narrow band of tile that stays warm while nobody is drawing hot water. Cold-side failures are quieter and get missed for months. A grout line darkens, a baseboard never dries out, a wood plank cups in one direction, a closet turns musty, and none of it sits directly over the break. Water spreading under concrete follows the path of least resistance and surfaces where the finish is weakest, sometimes a room away. A meter dial that refuses to settle with the building shut down is what confirms the loss is active.
Foundation drawings matter before concrete tools do. The city's project submittal requirements make the foundation plan show slab thickness, reinforcing steel size and spacing, and the tendon layout for a post-tension slab, and require the plan to use the foundation system recommended in the project's geotechnical investigation report. That report has to be project-specific, stamped by licensed professionals, and no more than three years old unless it is updated.
Practical consequence for a leak: the record of where stressed strand runs already exists on paper for slabs built that way, and finding it is part of the job. Cutting a tendon releases stored force and removes compression the slab was designed to keep. That is a structural decision belonging to whoever carries the foundation, informed by the drawings and by scanning, not a call made with a rented hammer.
The city's own geologic hazard work on the mesa communities is blunt about this. Very old paralic deposits, which cap the mesas, typically carry a thick clayey weathering profile that forms expansive, highly plastic residual clay. Expansion can produce unacceptable settlement or heave in slabs supported on grade. The listed causes of the moisture change that triggers it include precipitation, landscape irrigation, roof drainage, perched groundwater, drought and, in the report's own words, utility leakage.
So a slow leak under a slab is a soil event as well as a plumbing one. Floors that crack or lift months after a repair often reflect the moisture cycle the leak set off, which is a reason to fix a slab leak on evidence rather than to keep watching it. The same deposits are locally cemented, so the trenching around a house is often slower than the homeowner expects.
Resist opening a test hole at the damp spot, since moisture surfaces downstream of a break rather than above it. Do not run hot water to see whether the warm patch spreads, since every gallon travels under the floor into insulation and cabinet bases. Keep away from outlets, floor registers and appliance connections in a wet area, and stay out of standing water rather than reaching a valve through it. Closing the main from dry ground is worth doing, though a corroded stop should not be forced hard enough to snap.
Age explains the pattern. Census figures reproduced in the city's housing element put 7.3 percent of local units at 1939 or earlier, 16.6 percent in the 1940s and 1950s, and 33.7 percent between 1960 and 1979. The pre-war streetcar districts sit at the older end. North Park's original subdivisions were recorded just after the turn of the twentieth century, Kensington's pioneering subdivision dates to 1910, and Talmadge was established in 1925. Houses of that vintage began life with threaded steel supply and hubbed iron drainage, and both fail at the joint from the inside outward.
The mesa tracts are a different problem. Mira Mesa's first tract opened in 1969, and roughly 8,685 dwellings went up there between October 1969 and October 1976, an era of soft copper run in and under the slab. Hard water and a recirculating hot loop work on that copper from within while damp expansive clay works on it from outside.
Two honest answers exist. Opening the floor above the located point replaces the failed section, then leaves you patching concrete and matching a finish that may no longer be made. A reroute abandons the buried section, rebuilds the run overhead or through walls, avoids stressed strand entirely, and lifts the pipe out of the ground that failed it. A single failure in otherwise sound copper can justify the spot repair. A second failure on the same line, irreplaceable tile above it, or a tendon pattern with no clean window all argue the other way. Be equally skeptical of a whole-house repipe proposed from one located leak with no evidence of thinning anywhere else.
Hot is split from cold, each side is pressure-tested and watched for decay, ground microphones walk the floor, two sensor positions are correlated, and tracer gas goes into the drained section when carpet or thick tile defeats acoustics. Thermal imaging confirms the picture where the temperature difference supports it. The point is marked with measured offsets from two walls and photographed. Four things move the number: whether finished floor has to come up, whether one fitting or a rebuilt run is the answer, whether scanning and an engineer come first, and who restores tile, texture and paint.
Slab Leak Detection in San Diego. Call (619) 603-0192 and a technician is dispatched with the parts on the truck. You get the price before the work starts.
Call (619) 603-0192The City of San Diego says older private sewer laterals of concrete, clay, or cast iron can develop root intrusion or deteriorated sections, and that the property owner is generally responsible for maintenance of the lateral to the City sewer main.
Why it matters: Damp ground, odor, or a drainage problem does not automatically indicate a pressurized water leak. When the evidence points to an older sewer lateral, the investigation may need a cleanout or camera inspection instead of water-line pressure testing.
Source: sandiego.gov
The City's Water Facility Design Guidelines state that much of San Diego is exposed to a marine environment, where airborne salts and wet-dry cycling in chlorides can create significant corrosion activity on exposed metal surfaces.
Why it matters: At coastal and near-coastal properties, exposed fittings, valves, clamps, backflow assemblies, and pool or irrigation equipment deserve a close visual inspection before a hidden line is blamed or a deck is opened.
Source: sandiego.gov
City of San Diego Public Utilities says water pressure varies by location and demand. Under the California Plumbing Code, a property needs a water-pressure regulator when local pressure exceeds 80 psi, and the regulator is the property owner's responsibility.
Why it matters: San Diego's mesas, canyons, and pressure zones mean a reading from another address is not enough. A leak investigation checks static and flowing pressure at the property and tests the regulator before treating weak, surging, or excessive pressure as evidence of a failed buried line.
Source: sandiego.gov
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