Reply by MNgary

To help minimize sagging of the shelves, you could cut a half inch kerf legthwise and inset a one-half by one inch piece of angle iron a few inches from the front in addition to a cleat at the rear. But even so, I would consider two five foot shelves.

For deep uppers, you may want to install under-cabinet lighting so the countertop below isn’t in the shadows.

-- "I dream of a world where a chicken can cross the road and no one questions its motive"' - Anne Nonny Mouse