I am using a new wood shed this year (it is an old shed that was filled with junk that I cleaned out). I stacked most of the wood (3/4 of the shed), but towards the end, I just threw it in a big heap. Does firewood that is covered dry much slower if it isn't stacked but is simply piled up? The floor is thick concrete. My thoughts on the subject are that it won't make much difference. As many of us have discovered, stacking wood allows us to pile more wood in the same volume of space. Knowing this it seems as though there will be plenty of air space. The shed breaths well as it has open windows on all sides.