So i cant take credit for this; but i think i have improved a few areas. Note i used OSB particle; i have ALOT on hand, and my boxes for the most part are out of weather. I have made a few out of treated 1/2 or 3/4 solid plywood. These are at no cost to Me. this will be pic heavy. Also as this is just a diagram, i do caulk all joints to not allow any moisture.