The Silent Destroyer Under Your Foundation
It starts quietly. A water bill that's $50 higher than usual. A barely-warm patch on the kitchen floor that wasn't there last month. The faint sound of running water at 2 AM when everything is off. By the time most homeowners call a plumber, the leak has been running for weeks — sometimes months — silently eroding soil, saturating your foundation, and driving up costs with every passing day.
A slab leak is a pipe failure underneath your concrete foundation. In the Bay Area, where homes built from the 1950s-70s used copper supply lines embedded directly in concrete, these leaks are devastatingly common. The copper corrodes from the outside (where it contacts concrete) and from the inside (mineral deposits), creating pinhole failures that spray pressurized water 24/7 into the soil beneath your home.
"Our water bill tripled over two months. Two plumbers said they couldn't find the leak. GB Plumbing used thermal imaging and located it in 20 minutes — under the hallway, exactly where they said. Fixed the same day."
— Burlingame homeowner, Easton Addition ★★★★★
Warning Signs You Might Have a Slab Leak
Don't wait until you see water pooling. These early signals mean it's time to call for detection:
How We Find Your Slab Leak — Without Demolition
Other plumbers guess. We detect. Our multi-technology approach pinpoints the exact location of under-slab leaks so we only access the precise point of failure — not your entire floor.
Pressure Isolation Test
We isolate your hot and cold supply lines to determine which system is leaking. This narrows the search area by 50% immediately and confirms whether it's a supply line or drain line failure.
Electronic Acoustic Listening
Specialized ground microphones detect the sound of pressurized water escaping from pipe — even through 4+ inches of concrete. We map the sound intensity to locate the epicenter of the leak.
Thermal Imaging Scan
Infrared cameras detect temperature differentials in your slab caused by hot water escaping underground. This provides visual confirmation of the leak location with pinpoint accuracy.
Targeted Access & Repair
One small access point — typically 12-18 inches — is all we need. We repair the pipe, pressure test the fix, and restore the opening. No unnecessary demolition, no guesswork.
"I'd been told I needed to jackhammer my entire kitchen floor. GB Plumbing found the leak with their equipment in one spot under the laundry room. Small hole, quick fix, $1,200 instead of the $8,000 the other guy quoted. Night and day."
— San Mateo homeowner, Hillsdale neighborhood ★★★★★
Repair Options: Fix It or Bypass It Permanently
Once we locate your slab leak, you have two paths forward — both with distinct advantages depending on your home's pipe age and history:
Spot Repair (Direct Access)
Best for newer homes with isolated failures. We access the leak through a small opening in the slab, repair or replace the damaged section, pressure test, and restore the floor. Quick, affordable, and minimally invasive when the rest of your pipes are healthy.
Pipe Reroute (Above Slab)
Best for homes with aging pipes or repeat slab leaks. We abandon the under-slab pipe entirely and route new supply lines overhead through walls and attic space. This eliminates the risk of future slab leaks forever — a permanent solution for homes with copper pipes approaching end of life.
Full Repipe (Long-Term Fix)
If multiple slab leak locations indicate system-wide copper deterioration, a full repipe with overhead routing removes all under-slab piping permanently. Many homeowners choose this after their second slab leak — preventing the inevitable third and fourth.
Why Bay Area Homes Are Prone to Slab Leaks
The San Francisco Peninsula has a slab leak problem that many newer communities don't. Here's why:
- 1950s-70s construction era: Copper pipes were cast directly into concrete slabs — standard practice then, known failure point now
- Soil chemistry: Bay Area soils are mildly corrosive to copper, accelerating external pipe deterioration
- Water quality: Peninsula water is moderately hard, building internal deposits that create turbulence and pinhole failures
- Seismic micro-movement: Small tremors shift soil and stress rigid pipe connections buried in concrete
- Age: Copper embedded in concrete lasts 40-60 years. Most Bay Area homes are now 50-70 years old — right in the failure window
"Third slab leak in five years. GB finally recommended rerouting above the slab — best decision we ever made. Zero leaks in two years since. Should have done this after the first one."
— Millbrae homeowner, Mills Estates ★★★★★
Serving All Bay Area Communities
We detect and repair slab leaks throughout San Mateo County and southern San Francisco:
Burlingame · San Mateo · Hillsborough · Millbrae · San Bruno · Daly City · San Francisco (southern neighborhoods) · and surrounding areas.
Based at 1445 N Carolan Ave in Burlingame, we're centrally located for fast response anywhere on the Peninsula. Most detection appointments are available same-day or next-day.
Don't Let a Hidden Leak Destroy Your Foundation
Slab leaks cause $10,000-$50,000 in foundation damage when left undetected. A $300 detection today prevents catastrophe tomorrow. Call GB Plumbing now.
(650) 235-6443