San Francisco County · Detection
Pinpoint hidden leaks under concrete foundations without breaking up the whole slab.
Grace L., who lives in Mission District, San Francisco, reached out after noticing unexplained cracks in flooring, drywall, or the foundation itself. San Francisco has comparatively few true slab-on-grade homes compared to most California cities, since much of its housing stock is Victorian and Edwardian construction with raised foundations and crawlspaces rather than poured slabs, so slab leaks here concentrate in the mid-century construction found in outer neighborhoods like the Sunset District, built during the city's westward expansion in the 1940s-50s. A problem that had been dragging on for months was pinpointed in under two hours.
— Grace L., Mission District, San Francisco
San Francisco has comparatively few true slab-on-grade homes compared to most California cities, since much of its housing stock is Victorian and Edwardian construction with raised foundations and crawlspaces rather than poured slabs, so slab leaks here concentrate in the mid-century construction found in outer neighborhoods like the Sunset District, built during the city's westward expansion in the 1940s-50s.
Water service in San Francisco is provided by the SFPUC, and confirming whether an issue is on your private plumbing or the utility side of the meter is one of the first things we check.
A slab leak happens when a hot or cold water line running beneath your home's concrete foundation develops a crack, pinhole, or corrosion failure. Left alone, it can warp flooring, feed mold behind walls, and quietly inflate your water bill for months. Our technicians use acoustic listening equipment, infrared thermal cameras, and static pressure testing to find the leak's exact position before a single inch of concrete is opened.
Because slab leaks are hidden under structural concrete, guesswork digging is expensive and destructive. We combine electronic amplification with thermal imaging to narrow the leak to a small, marked area, so any follow-up access work is as limited and targeted as possible.
A hot spot on the floor, or one area of carpet or tile that's always warmThe sound of running water when every fixture in the house is offA water meter that keeps spinning with all taps closedUnexplained cracks in flooring, drywall, or the foundation itselfMildew smell or unexplained humidity in ground-floor roomsA steadily climbing water bill with no change in household usageFrom Sunset District, Richmond District, Noe Valley to Mission District, Pacific Heights, Bernal Heights, we handle slab leak detection calls across San Francisco, matching the approach to each property's age, soil, and layout.
Call or request an appointment online. Same-day slots are available across California for active leaks.
A technician arrives with acoustic listening equipment, thermal imaging, and pressure or camera tools matched to your specific leak type.
The leak's exact location is marked and explained to you in plain terms, so nothing gets opened up on a guess.
You receive a written diagnostic report you can hand to your plumber, restoration team, or insurance company, with repair or fix options discussed on the spot.
“Old Victorian with plaster walls everywhere, so I was dreading this. They used thermal imaging and found the leak behind one wall panel instead of opening up the whole room. Saved us a big repair bill.”
“Ground near our garage had been soft for a while. Turned out to be the main line. They marked the exact dig spot and our plumber only had to open a two-foot section instead of the whole path.”
“The floor in our hallway had a warm spot for weeks. They found the slab leak in under an hour with the listening equipment and marked a tiny area instead of tearing up the whole hallway. Huge relief.”
“Our water bill jumped for two months straight and we couldn't find why. Turned out it was a slow leak behind the water heater. Professional, on time, and explained everything on the spot.”
“Salt air had corroded a fitting outside near the meter box. They traced it with the acoustic equipment without digging up my whole side yard first. Appreciated the straightforward report.”
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