I have twelve pototao bin shelves now, these sit on top of a palett that sits over a gravel filled dirt area in our basement floor. That's Angel our sheltie in front of the bins.
Holes were drilled in the end boards of each bin shelf to aid in air flow, we used 1 x 2 inch fencing for the bin bottoms.
Dh stapled lathe to the bottom of the bins to make them easier to pull out and push back into place much like a dresser drawer.
He used 1 8 foot 2 x 4 to make each bin.