What Causes Water Damage Under a Kitchen Sink?

The flexible supply lines that bring hot and cold water to your faucet are a frequent source of leaks. These hoses can degrade over time, developing cracks or pinholes. The connections at the shutoff valves or the faucet itself can also loosen from normal use. Even a small, steady drip from these lines will soak the cabinet floor and surrounding materials, leading to hidden damage that may not be visible until the wood is soft or mold appears.

Garbage disposals can develop leaks from their housing or at the flange where they mount to the sink. The dishwasher drain hose, which often connects to the disposal, is another potential leak point. If the hose clamp is not tight or the hose itself is old and brittle, it can spray water during the drain cycle. These leaks often go unnoticed until significant water damage has occurred, as they happen inside a closed cabinet and only during appliance operation.

If you discover a leak, your first step is to shut off the water supply. Turn the valves under the sink clockwise until they stop. If those valves are stuck or also leaking, locate your home's main water shutoff. Then, dry the area as much as possible with towels. For any significant water, especially if it has soaked into wood or drywall, contacting local water damage pros is the next step. They have the tools to properly dry hidden areas and assess structural safety. Materials like particle board and drywall absorb water quickly, and trapped moisture can lead to mold in just a day or two.