I am considering installing wood plank over a concrete floor of my basement. Repeated 2 x 2' squares of 6 mm. plastic taped to the floor for 72 hrs. has not revealed any accumulated moisture, however, it is the middle of the winter here (lower New York state), and in the warmer six months of the year I need a humidifier running half speed down there. There is also some moisture between the inside window and storm window in the house above. Would anyone put a wood floor in? I would use a layer of 6 mm. plastic, then spacers (should the spacers be treated wood, and how thick?), 3/4" plywood (does it need to be sealed with a vapor barrier-type primer like Zinsser oil-base?), and then the wood. Thanks.