The Ditra-Heat-Duo provides a floor-warming and sound-control system in one single-layer underlayment system. Schluter says that the membrane is ideal for ceramic and stone tile installations, especially in multifamily buildings, and that it increases the impact insulation class of a concrete slab floor, reduces impact sound transmission, supports heavy floor coverings, and warms tiled floors faster over concrete substrates by directing heat to the tile, not to the subfloor. The flooring membrane is priced at $3.47 per square foot. schluter.com