Ted, I had the two level spots close to the mill & planer, thats the only reason. The 10 footer, as I sawed the 2x6's [the last 60 or so] I slid right on the back of my F350, then backed up to the stack & unloaded right on top. Any edges or ends that get a little wet from a wind blown rain will dry out just as fast. These won't be here long, and as a floor in a barn, it won't matter if there's a few water stains. Character, you know. I've found the depth of the stack to dry the least, some I made 6 ft wide years ago got somemold in the center, especially the sapwood. If I was drying some nice hardwood, I'd keep the stack 36 to 42 inches wide, at the most. As far as height, after 6 ft, it gets tough, but the ones down lower won't move for sure.