Kitchen sink leak water damage can start from a loose supply line, failed drain fitting, garbage disposal, dishwasher connection, sprayer hose, shutoff valve, or slow trap leak. The cabinet may look like the only wet spot while water is already under flooring, behind toe kicks, or inside the wall behind the sink.
Start by stopping the source if it is safe. Turn off the hot and cold sink valves, stop using the garbage disposal or dishwasher, and keep people away from wet outlets, under-cabinet wiring, and plugged-in appliances until the area is safe.
Document the cabinet before cleanup changes the evidence. Photograph the supply lines, drain, disposal, dishwasher hose, cabinet base, toe kick, nearby flooring seams, baseboards, wall stains, ceiling below, and any plumber or maintenance notes tied to the leak.
Remove stored items from the cabinet only after photos are taken. Do not assume the job is finished when the cabinet face feels dry. Particleboard cabinet bases, subfloor edges, laminate seams, hardwood, vinyl plank, and drywall behind the sink can hold moisture after the visible puddle is gone.
Escalate faster when the leak ran for more than a few hours, water reached flooring layers, the cabinet base is swollen or soft, there is odor, the ceiling below is stained, or the leak involved a dishwasher or disposal line that may have carried food residue or dirty water.
Keep the repair and drying records together. Save plumber notes, failed fittings, photos before removal, moisture readings, drying-equipment notes, and receipts so a restoration provider, insurer, landlord, or property manager can understand what happened and why materials were dried or removed.
Questions
What should I do first after a kitchen sink leak?
Turn off the sink supply valves if safe, avoid wet electrical areas, stop using connected appliances, document the leak and nearby materials, and check cabinet bases, flooring, walls, and rooms below.
Can a kitchen sink leak damage flooring or cabinets?
Yes. Sink leaks can soak cabinet bases, toe kicks, flooring seams, underlayment, subfloor edges, drywall behind the cabinet, and ceilings below before the surface looks wet.