SKIMFLOW® HPI is a unique polymer modified gypsum cement self-leveling underlayment for use over interior surfaces. SKIMFLOW® HPI can be pumped or poured and delivers high strength, good water resistance and outstanding adhesion. Applications from as thin as 1/8” and as thick as 3” depth can be achieved in a single pour. SKIMFLOW® HPI remains flow-able for nearly half an hour, yet will withstand foot traffic at any depth in about two hours. This product offers high density, yet less finished weight and more flexibility than Portland cement self-levelers.