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Laminate Worktop Swollen Around The Sink
The worktop has risen and gone soft or bubbly along the back or side edge of the sink, and the laminate is lifting.
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What's happening?
A laminate worktop is chipboard with a laminate face. The face is what resists water; the core is not waterproof at all. Everywhere the top has been cut — the sink and hob cut-outs, mitres, back edges, screw and tap holes — bare core is exposed, and EGGER's processing instructions are explicit that these hidden cut edges must be sealed during final installation with a sealant or a two-part product, because moisture reaching the substrate through them leads to swelling. Kitchen fitters call the result a blown worktop. It shows first as a raised, spongy strip behind or beside the sink, because that is where water pools and sits. Swollen chipboard does not dry back to its original size; the fibres have expanded permanently.
What usually causes it?
- The sink cut-out edge never sealed at installation, leaving bare chipboard exposed to every splash
- The sink's own sealing ring, gasket or clips not fitted as the sink manufacturer specifies
- Silicone around the sink rim gone hard, split or shrunk away, so water runs under the lip
- A slow drip from the tap tail, the tap base or the waste connection landing on the cut edge from below
- Water pooling behind a sink pushed tight to the wall, with no upstand or seal at the back edge
- A dishwasher or washing machine venting steam up into the underside of the worktop
- Standing water left after washing up, wicking into an unsealed edge over months
Is it dangerous?
No, but a swollen worktop is usually the visible end of a hidden wet patch. Damp inside a base unit and under a sink supports mould growth, and the GOV.UK guidance on damp and mould is clear that exposure to mould in the home carries real health risks, so it is worth opening the cupboard and looking rather than only judging what the top looks like.
Can I fix it myself?
Stop the water. Check the tap tails, the waste trap and the sink clips for a slow leak, dry the cupboard out, and rake out and renew the silicone around the sink rim with a mould-resistant kitchen sealant. What you cannot do is reverse the swelling — sanding, weighting or heating a blown chipboard core does not shrink it back, and cutting into it exposes more bare edge.
When should you call a kitchen fitter?
Call a kitchen fitter once the top has visibly risen, when the laminate has lifted or split, or when you want the sink lifted out to seal the cut-out properly. A fitter will tell you whether the length can stay or has to be replaced, and will seal every exposed edge on the new one so it does not happen again.
What will the kitchen fitter actually do?
- Lift the sink and tap out to expose the full cut-out edge and the underside of the worktop
- Trace the water path — cut edge, rim seal, tap tails, waste or an appliance vent — and fix the source
- Advise honestly whether the swelling can be lived with or the length needs replacing
- Seal all exposed cut edges, drill holes and the back edge as the worktop manufacturer specifies
- Refit the sink with its own gaskets and clips, and re-seal the rim with a mould-resistant kitchen sealant
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