Originally Posted by
Jamie Buxton
If you fasten a big area of solid lumber, like flooring, to a sheet of plywood, you may get into trouble. The lumber expands and contracts across the grain with changes in atmospheric humidity. If you edgeglue the flooring to make one continous sheet, you'll likely see warping in the table top. If you don't edgeglue the flooring, you're a little less likely to see warping, but you're more likely to see gaps between the boards. That's not nice for a desk surface, where you may be writing.
You might consider using hardwood-veneered plywood for the top. No gaps, and no warping. You still have to edgeband it, but you'd have had to do that with the flooring idea. Or you could use just solid lumber for the top. That gets you out of the edgebanding step. But you do have to allow the top to grow and shrink a bit against whatever base you have.