It's worth being direct about this one: a swollen section of worktop cannot be repaired back to its original condition, because the swelling is the board's internal structure permanently altered by absorbed water. The only proper repair replaces that section.
Where this repair often goes wrong is stopping at the replacement and not addressing why the water got in there in the first place, which just sets up the same failure again in a year or two.
What has to be opened up
The sink, and often the hob if it's involved, has to be disconnected and lifted out to properly assess and replace the affected worktop section, and to get proper access to reseal the joint and cut-out correctly.
The correct sequence of works
Every water route into the board needs closing, not just the one that's currently causing visible damage.
- Remove the sink and any affected worktop section rather than attempting to dry or patch the swollen area
- Cut and fit a new section of matching worktop, jointed correctly at the required distance from the sink or hob cut-out
- Seal every cut edge — the cut-out perimeter and the new joint — fully before the sink or hob goes back in
- Refit the sink with a proper, continuous seal rather than reusing old sealant or a partial bead
Why a cosmetic patch doesn't hold
Sanding down the raised joint and resealing the surface might make it look flat again briefly, but the board underneath is still swollen and still moisture-damaged, and the route the water used to get in is very likely still there. It will swell again, usually faster the second time because the board is already compromised.
Interfaces with other trades
Sink refitting involves the plumbing connections being disconnected and reconnected, so this is usually coordinated with whoever fitted the original plumbing, or done as one visit if the same trade handles both. Hob cut-outs may also need an appliance engineer if there's a gas or electrical connection to isolate.
How you know the repair has worked
Check the new joint and sink seal for any sign of water sitting or tracking after normal use over the following weeks — no darkening, no rising edge. A properly sealed joint and sink fitting should show no change in appearance under ordinary daily use.
Common questions
Can I replace just a small patch rather than the full section?+
It's possible for small areas away from a joint, but where the swelling has affected a joint itself, replacing the full jointed section gives a far more reliable, better-matched result than trying to patch a small area.
Should I choose a different worktop material this time?+
It's worth considering if the original specification wasn't well suited to being right next to a sink. Some materials handle repeated water exposure at joints and cut-outs considerably better than others.
How do I stop this happening again after the repair?+
Beyond the sealing work itself, wiping standing water away from the joint and cut-out area routinely, rather than letting it sit, reduces the chance of water finding any small imperfection in the seal over time.
Get a written quote for a proper worktop repair
We'll replace the affected section, reseal every joint and cut-out properly, and refit the sink so it doesn't happen again.