Conference Table

[Kevin Jenness]

If you use the wood shrinkage calculator at woodweb with a 4% change in moisture content in plainsawn white oak you get a prediction of 1.8" movement in a 120" wide piece. The actual movement will no doubt be less as the grain orientation will not be purely tangential, but still a lot to plan for. If you have not yet glued up your parts you may want to turn them to a rift/quartered orientation as far as possible to reduce movement. There is a reason solid wood tables are typically built with planks running in the long direction.

How are you measuring the mc of your wood? Pin meters are not reliable below 6%.

It is always a good idea to know the projected in-service conditions for your work. I am guessing that in your location air conditioning is standard and the emc may well be 8% or so, but an unconditioned space may lead to much higher movement. You might want to let your wood acclimate to a higher relative humidity. What is the normal rh in your shop and how do you regulate it? If your lumber is stable at around 5-6% mc that would indicate an rh of 25% or so.

Unless you encapsulate your top in epoxy it will gradually move to match any seasonal humidity swings.

The one advantage of your design is that making the top in two pieces for easier transport will make only a minor difference in the overall look of the installed piece.