Worktop Cracked At The Hob Or Sink Cut-Out

What's happening?

A cut-out corner is a stress concentrator. Every cut-out puts a sharp change of direction into a sheet that is under tension from its own laminate and, at a hob, from repeated heating and cooling. EGGER's processing instructions require cut-outs to be rounded rather than square, precisely because sharp corners have an adverse effect on the material and lead to crack formation, and they single out the hob area where frequent heat causes increased shrinkage tension as the laminate dries out. Their instructions also call for the cut to be made from the underside so the laminate does not chip, and for the raw edges to be finished. A crack from a corner is almost always the cut-out geometry rather than the worktop material: the same top elsewhere is fine.

What usually causes it?

• Cut-out corners cut square or with too tight a radius instead of being properly rounded
• The cut-out sawn from the top face, chipping the laminate and starting a crack at the corner
• Raw cut edges left rough and unfinished, so small chips grow under thermal movement
• Heat from the hob cycling the laminate and building shrinkage tension around the opening
• Hot pans set straight onto the laminate beside the hob rather than on a trivet
• Base units out of level or unsupported under the cut-out, so the weakened area flexes
• The hob or sink clamped down too tightly, loading the edge of the opening

Is it dangerous?

A crack beside a hob is worth taking seriously. It exposes the chipboard core right next to a heat source, and next to a sink it lets water straight into the core. Neither is an immediate hazard, but both get worse quickly and a crack that has reached the edge of a cut-out can let the hob or sink move in its opening.

Can I fix it myself?

Very little. There is no filler that restores a laminate surface across a crack, and drilling a stop hole at the crack tip (the usual suggestion online) puts another unsupported edge into the same stressed area. Keep hot pans off the affected area, keep water out of the crack, and stop the hob or sink being loaded until it has been looked at.

When should you call a kitchen fitter?

Call a kitchen fitter when a crack has appeared at any cut-out corner. They will judge whether it is stable or spreading, whether the units under it need supporting, and whether the length has to be replaced, and if it does, they will cut the new one with radiused corners from the underside so the same crack does not appear in a year.

What will the kitchen fitter actually do?

• Lift the hob or sink to see the full extent of the crack and the state of the cut-out edges
• Check the base units beneath the cut-out for level and support and pack them where needed
• Advise whether the crack is stable or the length needs replacing, without patching a spreading one
• Cut any replacement from the underside with properly radiused corners and finished edges
• Seal the cut-out edges, protect the hob opening as the worktop manufacturer specifies, and refit the appliance to its own instructions

Who fixes this

• Worktop replacement

Questions people ask

Sources & References

1. EGGER: How to join and seal laminate worktops
2. EGGER: Laminate worktop FAQs (heat and durability)
3. EGGER Worktops: processing and installation instructions