Marta noticed it while picking a dropped teaspoon off the floor. From standing height, her laminate worktop looked fine. From teaspoon height, the underside above the dishwasher looked like a tired breakfast biscuit. We were there to fit a new end panel, and suddenly the old counter had a vote in the plan.

Check where the moisture starts

Do not assume every damaged patch above a dishwasher is steam. A leaking connection, water running from the sink, a damaged door seal or an installation problem can leave similar clues. Note whether the area becomes damp during the cycle, when the door opens, or after someone uses the sink.

Avoid repeated test cycles if water is escaping. If there is an active leak, stop using the appliance and arrange service. Keep hands away from wiring and do not pull a connected machine out just to get a better photograph.

That protective strip is doing a job

Some installations specify a strip, sheet or plate beneath the worktop. IKEA's FENSJÖ diffusion barrier is one example designed to protect the underside of a counter from hot steam released when an appliance opens. The right protection and its position depend on the countertop and dishwasher instructions; one product is not a universal fix.

Have the installer check that the specified part is present, intact and fitted where it belongs. A sheet buried too far back, or attached over dusty damaged material, may not protect the vulnerable front edge. Do not seal over appliance vents or substitute an improvised sheet that interferes with the door.

Repair the cause before the surface

  • Photograph the damage and nearby joints before anything is covered.
  • Have the appliance checked if there are leak, seal or door-operation symptoms.
  • Assess whether the counter material remains sound enough for a repair or needs local or wider replacement.
  • Restore the required moisture protection on a suitable prepared surface, then verify normal operation.

Swollen particleboard does not return to its original strength because the surface dries. Filling and painting may hide the outline while leaving a weak edge. The sensible scope depends on how far the damage goes, where the counter is supported and whether a joint is involved.

Leave the machine a way out

Marta's damage was local, but the end panel could not simply be fitted over it. We paused that part of the job, coordinated the counter repair with the appliance check, and kept the dishwasher removable. The teaspoon went back in the drawer; the photograph stayed in the job notes.

Before finishing the surround, check the dishwasher's removal path and drain-hose routing. If the kitchen has timber counters nearby, the sink-area wood guide explains the other edges worth protecting.

Follow the dishwasher maker's normal drying and door-opening instructions. Models that open automatically are designed around that feature; blocking it or inventing a different routine is not a repair.