Been doing a little shop design here and there. Finally got what I think might be a workable size. Now I am thinking about the floor. I want a wood floor. Tried of sore feet and back, after a day in the shop. I am looking real hard at the unfinished seconds from Lumber Liquidators. 89 cent a sq ft and would go well in a shop. Question is, how do I put it down, over the concrete. The pad will be poured level, with no drainage, so that issue is out. Thinking treated 2x4 16" on center flat, then 5/8" OSB, then the 3/4" floor. Is this over kill? It would get me little over 2 3/4" to run some electric in the floor. Guessing I would need vapor barrier before the 2x4 or after?