Visible leak guide

Under-Sink Leak: Contain It and Find the Pattern

A bucket buys time; it does not identify whether the source is a supply valve, drain fitting, disposal, seal, or damaged component.

Check this drain problem

What this pattern often looks like

  • A drip appears only while the sink drains.
  • A fitting or trap is visibly wet.
  • The leak is small enough to contain without entering a damaged area.

Signs to stop and call

  • Water is near an outlet, disposal connection, dishwasher, wall, or floor cavity.
  • A supply line is spraying or flowing continuously.
  • Cabinetry, flooring, or a ceiling below is swelling or stained.

Safe checks

  • Place a bucket and towel under a small accessible drip only if the area is dry and safe.
  • Stop using the fixture and photograph where moisture first appears from a dry location.
  • If a visible supply line is leaking and its accessible shutoff turns easily, close it gently. Never force a stuck valve.

Do not do this

  • Do not touch electrical equipment with wet hands or from a wet surface.
  • Do not tighten unfamiliar plastic fittings until they crack.

What to tell the plumber

Water appears under my sink when [activity]. It seems to begin near [location], and there [is/is not] visible cabinet or floor damage.

Related visual tip

Contain the drip before chasing the fitting.

A bucket buys time and a clear photo helps identify whether water appears while the fixture fills, drains, or sits unused.

These are general observations, not a diagnosis. Active flooding, rising sewage, water near electricity, gas smell, or structural damage requires qualified local help.