Sink Leak Detection & Repair in Beaverton, OR

Sink leaks are deceptively quiet failures. A dripping faucet announces itself with every drop, but a failing drain connection under the sink, a slow weep from a supply hose, or a degraded caulk seal between the sink and the countertop all lose water in an enclosed space -- inside a cabinet, behind a panel, or into the subfloor. In Beaverton homes where kitchen and bathroom cabinets sit on wood subfloors, enclosed sink leaks can produce significant wood rot and mold growth before any visible surface evidence appears. By the time a homeowner notices a warped cabinet floor or a musty odor under the sink, the leak has typically been active for weeks or months.

The Pacific Northwest climate makes this worse. Beaverton's ambient humidity during the October-May wet season -- consistently high even inside the home -- means that moisture that would dry out quickly in a drier climate persists much longer in a Beaverton cabinet space. A slow drip that wets the cabinet floor twice a day in a Murray Hill kitchen can maintain enough moisture to sustain mold growth without ever producing standing water. Detection of early-stage under-sink leaks in Beaverton homes requires moisture metering the cabinet walls and floor in addition to visual inspection.

Supply Side: Connections Under the Sink

Every kitchen and bathroom sink in Beaverton has two supply connections: a hot water line and a cold water line, each running from a shutoff valve (angle stop) to the faucet body through a flexible supply hose. These connections are the most common source of under-sink moisture in Beaverton homes, and also the most preventable. Braided stainless supply hoses have a rated service life of approximately 10-15 years; the hoses under a sink installed in a 1995 Murray Hill kitchen remodel are now 30 years old and well past that rating.

Failure modes at supply connections include: hose body cracking or bulging (the woven sheath masks the inner hose condition until failure), compression fitting corrosion at the shutoff valve, and fitting thread failure at the faucet body inlet. We check all under-sink supply hoses and shutoff valves for corrosion, fitting condition, and hose body integrity on every sink assessment call -- replacing an aging supply hose proactively costs far less than replacing a rotted cabinet floor. For supply hose failures that have already caused cabinet damage, our faucet leak repair service includes damage documentation.

Drain Side: P-Trap, Drain Basket, and Disposal Connections

The drain side of a kitchen or bathroom sink carries only gravity-flow water, but that does not mean it is leak-free. The drain basket (the assembly connecting the sink basin to the drain pipe) can fail at the putty seal between basket and basin, at the lock nut below the basin, or at the basket body itself if corrosion has eaten through. A failed drain basket seal leaks every time the sink is used -- the water appears at the bottom of the cabinet and is often misidentified as a supply connection leak because the two occur in the same space.

The P-trap (the curved pipe section below the drain that creates a water seal against sewer gas) uses slip-joint connections in older installations. These connections rely on rubber washers that harden and fail with age. In pre-1990 Central Beaverton and Cedar Hills homes with original chrome or galvanized P-trap assemblies, both the trap body and the washers may be at end of life. Plastic P-trap assemblies in newer homes are more durable but can be cross-threaded during under-sink access for other work, which produces a leak at that joint only.

Garbage disposals add a third failure point: the flange connection between the disposal inlet and the drain basket can develop a leak at the mounting ring seal, producing water at the disposal body during drain use. See our garbage disposal leak repair page for assessment and repair detail.

For sink leak detection and repair anywhere in Beaverton or Washington County, call (503) 974-3329. We serve all 29 areas including Cedar Hills, Murray Hill, and Central Beaverton. If an under-sink leak has already caused cabinet damage, we document the extent of moisture penetration before the repair begins.

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