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Why Is My Laminate Worktop Swelling Around the Sink or Tap?

For chipboard-core laminate worktops that have started to bulge, swell or lift around a sink cut-out, tap hole or wet edge.

By Home ManualReviewed 4 September 2026Safety level S1UK guidance
Quick answer

What this usually means

Swelling in a laminate worktop usually means water has reached the fibreboard core through an unsealed cut edge, failed sink seal, tap hole or damaged laminate. Once the core has expanded it rarely returns fully to its original shape. Dry the area, stop the water source and check the sink/tap seal, but do not simply cover active swelling with more silicone. Minor edge damage may be stabilised, while badly swollen material around a sink often needs the affected section or worktop replacing.

Likely causes

What may be causing this

1

Water is entering an unsealed or failed sink cut-out edge

Clues: Swelling follows the sink perimeter and silicone is split, missing or detached.

What to do: Stop the leak and have the cut edge and sink seal renewed correctly.

2

The tap base or tap hole is leaking

Clues: The worktop is worst immediately around the tap and water appears under the tap base.

What to do: Repair the plumbing leak and reseal the tap penetration after the substrate is dry.

3

A chip or damaged laminate surface has exposed the core

Clues: Swelling starts at a damaged edge or chip where water can reach the fibreboard.

What to do: Protect minor damage promptly; replace badly expanded material that cannot be made sound.

Diagnose the pattern

How to check what is happening

Dry the surface and watch where fresh moisture first appears
Water returns at the sink or tap seal

Active water ingress is still present.

Inspect the underside of the sink cut-out where accessible
The core is dark, soft or swollen

Water has penetrated the substrate.

Press only gently on the swollen area
The material feels soft or crumbles

The core is significantly damaged and repair may not be durable.

DIY decision

Can you fix this yourself?

Drying the area and checking visible silicone is reasonable. Plumbing leaks, sink removal and replacement of structurally swollen worktop sections are better handled by a kitchen fitter or plumber.

You'll usually need:
  • Dry cloth
  • Torch
  • Camera or phone
Step by step

What you can safely try

  1. 1

    Stop the water source

    Fix any active sink or tap leak before attempting cosmetic repair.

  2. 2

    Dry the substrate

    Keep the area dry and ventilated so you can judge the true extent of swelling.

  3. 3

    Inspect sink and tap seals

    Look for failed silicone, gaps or damaged cut edges.

  4. 4

    Decide whether repair is realistic

    Soft, expanded core around a sink usually needs replacement rather than surface filler.

Stop conditions

Call a kitchen fitter if…

  • The sink or tap is actively leaking into cabinets below.
  • The worktop is soft enough that the sink fixing is no longer secure.
  • Electrical sockets or appliances below are being wetted.
Still need help?

Get the right professional.

This problem can have more than one cause. Start with the checks above: a kitchen fitter is the usual first route, while a plumber may be more appropriate when the clues point that way.

Find a kitchen fitter →
Evidence

Sources used for this guide

We prefer primary UK guidance, regulators and manufacturers for technical and safety-sensitive claims.

  1. Laminate Worktop Installation InstructionsWorktop Express
  2. How to Repair a Chip in Laminate Kitchen Work SurfacesWorktop Express

Last reviewed: 4 September 2026. Home Manual updates review dates only when the substance of a guide is checked or changed.

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