Underlay is the layer of material directly beneath your floor covering. If you were to tear up the flooring in your home, you would likely find many layers. When you removed the floor covering, also called the finish floor, you?d expose the underlay. Remove that, and you would find a subfloor such as OSB (oriented strand board), plywood or concrete. A moisture and/or vapor barrier might be found among the layers too, especially in basement flooring, or the underlay might include a barrier in ... Read more
