How much verticle strength (stiffness) results when 2 or more layers of 1/2" or 3/4" plywood are laminated with 8' joints staggered each 4' on the adjoining plywood for a total length of 26' 8" at heigths of 12" and 16"? These are to be glued, screwed, and bolted to the sides of a boxed 2X10 frame 3' X 26' 8".