HeatBloc-Ultra is an aluminum colored, water- based, low emissivity (low-e) coating. When applied to building materials such as plywood, OSB or plasterboard, HeatBloc-Ultra lowers their surface emissivity to 0.19 or lower, blocking over 80% of the radiant heat trying to enter the home. It is classified by ASTM as an Interior Radiation Control Coating (IRCC). Meets 2010 Florida Building Code: Energy Conservation.