First let's establish the end goal. If your situation is different you'll be able to brainstorm a bit to accomplish the same thing.
End GoalSolid wood countertops and table tops expand and contract with changes in the climate. When the heaters come on in the winter or go off in the spring/fall the top will grow or shrink in size. The installation needs to allow this change. If the top is locked into place it will find a weak spot and crack or check. So the end goal is to allow some horizontal movement with very little or no vertical movement. Take a minute and watch the video below.
Do you have a cupped countertop?If your top sat around for a few days or weeks before being screwed down you may find it has cupped a bit. If so follow the same installation process but you'll want to slowly crank it down until it's flat. You can do this daily by bringing the screws down more and more until the top is snug to the cabinet top. Being too aggressive can damage the top. NOTES:
- End grain construction changes dimension the most. Allow for extra movement for these tops both in the installation and the design. If normal overhang is 1" spec 2".
- Parts of the country that have harsh winters like Chicago or hot dry air like Phoenix will need to allow for extra movement. You should also let the top acclimate to its climate for a week or so before screwing it down.