KOSTER KnuLevel is a high quality, self-leveling, fast setting, cementitious underlayment intended for interior use on concrete floors. It is easy to mix, pour, and spread, producing a smooth, level surface ready to receive flooring systems. It is walkable in 3-4 hours. KOSTER KnuLevel is intended to be applied onto a cementitious substrate.KOSTER KnuLevel accepts most major types of floor coverings and iscompatible with most adhesives. It is not intended as a wearingsurface. Do not use over KOSTER VAP I®2000 moisture controlsystems.