I could use some advice on laying carpet over concrete in my basement. The entire basement is 7 feet below grade and my concern is mildew/rot/ ordor over time. I have never had any water problems in the basement. I have placed a rubber mat on the floor and examined underneath after it had been down for several days. I see a slightly darker area where the mat had been, so I know their is some dampness if not allowed to evaporate. Any help would be appreciated.