How to Fix a Bowed or ‘Cupped’ Worktop: A Worktop Express® Nutshell Guide
- Our wooden worktops are kiln dried to reduce moisture content to 8 -10%; however this may fluctuate due to the nature and structure of wood (which reacts to its environment). Wood expands and contracts with changes in the surrounding humidity and – to a lesser degree – temperature. More humid air will cause wood to expand and drier air will cause wood to contract. Your worktops will acclimatise to the surrounding conditions and any changes in relative humidity and temperature may cause your kitchen worktop to warp. Worktops should be stored in the area of installation from the outset or, if stored in another area initially, should rest in the area of installation for at least 3 days prior to installation. Worktops transported from a different surrounding and installed immediately are especially prone to movement and warping.
- On rare occasions timber worktops may bow once installed. Almost always this is as a result of incorrect fitting, which restricts the wood’s natural contraction and expansion. The release of moisture in the room (from appliances such as tumble dryers) and insufficient protection may also cause damage.
- Begin the process by oiling your worktops with the recommended Rustins Danish Oil (please see our guide to worktop maintenance for more information). This will seal the timber in preparation for installation. Ensure you apply at least three coats (with 6-8 hours of drying time in between) to the faces, and six coats to the end grains.
- Fix the back end of the worktop to the supporting base units sitting beneath it. Make sure you’re only using the slotted angle brackets –any other fixing bracket will restrict the worktop’s natural movement. Use the slot that runs perpendicular to the direction of the grain pattern (across, not parallel with it).
- Slowly and gently pull the worktop down using clamps and battens. It’s important not to rush this stage – the timber will split if you use too much force – and be patient: this part of the process can take 1-2 weeks.
- Once the worktop has been pulled down, secure the front edge, too. Your worktop should be back to its natural shape now.
Fixing a bowed worktop that has already been installedmoisture barriers fitted above relevant appliances will prevent changes in humidity from affecting your worktop, and sufficient oiling to the underside of your worktop will also reduce potential damage, too. You should leave at least a 30mm gap between the end cap and a heat source such as an AGA or freestanding oven to protect the end grain from exposure to excessive heat. If you require any further advice regarding your worktops, please do not hesitate to contact us – we’re always here to help. Please note: this guide was updated on 27th October 2014 to reflect recent changes to the products utilised in our pre-oiling process. For more information on the changes, please visit our Improvements to our Pre-Oiling Service for Wooden Worktops blog post.
Please Note:This guide was originally posted on 20th November 2013 and was updated on 3rd August 2017 to include additional information.