None, moisture issues on a basement floor cannot be solved by covering it up. Any company that claims that is just covering up the issue temporarily (6 mo. to 2 years). What they are doing is postponing the issue that may be worse at a later time. Many claim that placing moisture barriers between the concrete and the floor that is being installed will solve the problem. In reality, what they are doing is trapping the moisture or vapor between the concrete and the moisture barrier. Over time, mold will eventually grow between the concrete and barrier. According to the US Department of Energy best practices, moisture should be allowed to dry into the room. Trapping the moisture on the surface of a retaining wall or floor is not recommended.