The M-D Multi-Floor underlayment system provides a durable subfloor preparation under all floating floor surface materials such as laminate, hardwood, carpet and, luxury vinyl. M-D Multi-Floor can be installed both on-grade and below-grade as well as over concrete and plywood substrates and saves installers time as it does not require fasteners. The underlayment also features elastic spring technology, allowing for dynamic compression when walked on and release when pressure is removed, thus delivering a comfortable walking surface.