This video describes the process of installing a moisture barrier over a concrete subfloor. The presenter is using 6 mil thick poly barrier. The barrier comes in rolls about twenty-four inches wide. When rolling out the moisture barrier you want to go from wall to wall and cover the entire floor. For optimal moisture control you will want to overlap the poly barrier by at least six inches. The barrier plastic does not need to be taped or secured to the floor at all, it simply lays on top of the concrete. With the moisture barrier in place, you will not have to worry about moisture seeping up through your floor when you put down the top layer.