We have a 12' x 26' patio enclosure in a dry Colorado climate. The room is very well insulated but the floor is concrete. We would like to put indoor/outdoor carpeting out there but are not sure how best to prep. the concrete for installation. A full subfloor is not possible. We're considering plywood as a thermal break or just installing a thick pad and carpet directly over the concrete. What can we do to prevent mold, mildew, ect. from spills, wet boots, etc? Is it best to go right over the cement? Should we use plywood on top of the cement? Is there a special pad to prevent mildew or maximize carpet ventillation?