How to Repair Water Damage Under a Kitchen Sink in a Home
How to repair water damage under a kitchen sink is a small-looking job that often hides a swollen cabinet floor, a wet toe-kick, and a section of finished flooring that wicked water outward. The first step is the leak: a supply line, a drain trap, a disposal connection, or a dishwasher stub-out. This page is residential. A homeowner can handle a tiny, clean, recent drip. A soft cabinet, dirty water, or a floor that has started to cup is professional work. We refer independent contractors. We do not promise a cabinet-refinish result.
Stop the water, empty the cabinet, and see what is actually wet
A dark cabinet floor can be a stain from an old drip or a soft panel that is still wet today.
Shut the fixture supplies. If you cannot, shut the main. Remove cleaners and a wet wastebasket. Photograph before you pull the cabinet bottom, if you go that far, for insurance. A supply leak is often a failed stop or a loose connection; a drain leak is often a slip-joint or a disposal. A plumber may be the first trade. The restoration question is the box, the wall at the back, and the floor under and in front of the sink.
Particle-board cabinet floors swell and often cannot be saved. Plywood bottoms sometimes can, after a dry-down. The toe-kick and the adjacent hardwood or vinyl are part of the same loss. Check the wall behind the pipes with a meter if you have one; a wet drywall back can mold while the cabinet face looks fine. See wall water damage and drywall repair, and the kitchen-adjacent hardwood page if the floor is wood.
Dishwashers and ice lines
The leak may not be the sink you are looking at.
A dishwasher supply or an icemaker line in the same run can wet the same cabinet. Follow the water, not the first fixture you see.
Insurance and a 'slow leak'
A sudden failure and a cabinet that has been rotting for a year are different claim stories.
Document what you find. See the insurance guides. Do not invent a burst if the materials show a long-term leak.
Repair order: dry, then cabinet work, then the finished floor
Putting a new cabinet bottom on a wet subfloor is a short-lived fix.
Dry the space. Cut out ruined particle board. Check the subfloor. Only then rebuild the cabinet floor or replace the box. Finish flooring follows the same dry standard as elsewhere in the house. Educational costs sit on the main cost pillar. If the loss is larger than one cabinet, use the cleanup and process pages.
Frequently Asked Questions
Answers about cabinets, adjacent floors, and when a sink leak is more than a towel job.
For a small clean drip, a tight connection, and a sound plywood bottom, often yes. For a swollen box, a wet wall, or a cupped floor, you want an assessment.
No. Particle board bottoms often are. The box and the doors may still be fine. An honest scope names the parts.
It may be. It may also be an old sponge or a leak at the trap. Inspect and dry. See mold after water damage if growth is visible.
Usually not for a whole kitchen after a single-cabinet leak. A covered sudden loss may pay for damaged parts. Ask the carrier. Our pages are educational.