You notice when you go to a wood store, the boards usually stand up without a problem, but they are not on concrete, they are on wood platforms at a minimum of 8 inches off the cement. Cement always contains moisture, even in the desert, and moisture wicks into wood best through the ends of the board, thus the boards should not be standing on the cement. The moisture will not necessarily warp the wood while it's standing there, but when you go to build something, the wood closest to the floor will shrink and the wood at the top will not, which is a problem in the future, so it is a definite no no...being on the cement. Find a couple little pallets in a back alley and stack them with a piece of plywood on top, then stand your wood back up. You can build a little lip too, to stop the boards from sliding out if you want.
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Jeff Powell
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