QEP 72001Q Natural Cork Underlayment 1/2 inch Sheet 150 sq. ft. (25 sheets) Reduces sound transmission from both the surface of a floor as well as through the floor to living spaces below Use under ceramic tile, stone, marble, engineered hardwood and laminate floors Acts as a crack isolation membrane that resists transfer of stress cracks from subfloor through to flooring surfaces Reduces thermal transmission, increasing the effectiveness of floor heating systems Easy to install in both glue-down and loose-lay configurations