The difference between a $300 pipe repair and a $3,000 drywall-and-remediation project is often just whether the leak was found before or after excessive wall opening. Our Leak Detection service in Altadena uses the same detection methods utilities and insurance adjusters rely on — to pinpoint the failure location before anything is cut.
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A pressure test tells us a leak exists and how much water is escaping. Detection equipment tells us precisely where.
Acoustic detection is most effective on metal pipe (copper, cast iron) under slab or in concrete — materials that conduct sound efficiently. It works in quiet environments and requires shutting off the house briefly to establish a clean acoustic baseline.
Active water leaks — hot or cold — create a temperature differential on the surfaces they contact. An infrared camera shows these differentials as color-coded heat maps, revealing the wet zone inside a wall or under a floor without any cutting. A cold water leak behind drywall appears as a spreading blue-gray cool zone; a hot water leak shows the inverse.
We isolate the supply system, pressurize it to operating pressure, and monitor pressure over a timed hold period. Any pressure drop confirms active water loss from the supply side. By isolating zones — hot side vs. cold side, section by section — we narrow down which branch of the supply system is leaking before the detection phase begins.
For leaks that don't produce sufficient acoustic signature — very slow leaks, polyethylene pipe, or leaks deep under concrete — we can introduce a nitrogen/hydrogen tracer gas mixture into the isolated pipe and use a calibrated gas detector at the surface to find where the gas escapes. The detection sensitivity can locate leaks that produce no discernible pressure drop during a standard timed test.
Hidden leaks occur in different locations throughout a property — each requiring a slightly different detection approach. Here's how we handle the most common scenarios in Altadena, CA.
Confirmed slab leak location is documented with a marked point on the floor and provided to you in the written detection report, with coordinates relative to fixed reference points for the repair crew.
We document the thermal anomaly, mark the approximate pipe location, and recommend a minimal access cut rather than a wide wall opening.
Supply lines between the meter and the structure run underground and are vulnerable to corrosion, ground movement, and tree root damage. A main supply line leak shows as unusually high meter usage with all interior fixtures off, sometimes with wet ground or sinkholes along the line path. Acoustic detection locates the failure in the buried line precisely enough to minimize excavation footprint.
Pool plumbing — suction and return lines buried between the equipment pad and the pool shell — can develop leaks at fittings or in the pipe body that appear as unexplained water loss. We pressure-test the pool plumbing circuit, isolate the return and suction lines separately, and use acoustic detection to find which line and where.
Multi-story buildings, commercial kitchens, retail spaces, and industrial properties have complex pipe networks where a supply or drain leak can go undetected through multiple floors before surfacing. We approach commercial detection systematically — zone by zone pressure isolation, thermal scan of suspect surfaces, and acoustic confirmation.
We format detection reports specifically for insurance submission and can provide documentation on our detection equipment and methodology to claims adjusters on request.
Finding a hidden leak isn't a single step — it's a protocol that combines water loss confirmation, zone isolation, and targeted detection in sequence.
We start at the meter. All fixtures off, we watch the meter for 10 minutes. Movement confirms active water loss from the supply side. We also check for any visible evidence — water stains, soft floors, moisture readings with a moisture meter at suspect wall surfaces.
We isolate the supply system into zones — hot side, cold side, and if possible, individual branches — and pressure-test each zone to determine which branch is losing water. This narrows the area of active search significantly before detection equipment is deployed.
We document findings with thermal images and note detection readings at multiple grid points to triangulate the strongest signal.
Insurance claims: the report is formatted to support a claim for water damage from a concealed leak. We can provide supplemental documentation on request.

My water bill doubled over three months with no change in usage. Masters Plumbing Service came out, confirmed the meter was moving with everything off, isolated the cold supply to the kitchen as the failing branch, and used the acoustic device on the slab to pinpoint a location 4 feet from the outside wall under the kitchen floor. The repair crew opened a 10-inch circle in the tile, found a pinhole in a copper elbow exactly where detection said it would be. I was skeptical acoustic detection was that precise — it was.
Our insurance company required professional leak detection documentation before approving the claim. Masters Plumbing Service's written report with pressure test data and thermal imagery was exactly what the adjuster needed. Claim approved. The detection cost was covered as part of the claim.
Commercial building where water costs were running 40% above baseline for six months. Masters Plumbing Service ran a systematic zone-by-zone pressure isolation across four floors, narrowed the loss to the third-floor kitchen supply branch, and located the failure with thermal imaging at a concealed valve body in the ceiling. No damage to the finished ceiling.

Masters Plumbing Service provides professional Leak Detection for residential and commercial properties throughout Altadena and the surrounding Altadena, CA service area. Detection appointments available most weekdays and Saturdays.

Masters Plumbing Service's detection team finds hidden leaks in Altadena homes and commercial properties using equipment that eliminates guesswork. The detection appointment pays for itself the moment it prevents one unnecessary wall opening.
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