Costarthermal B12 is a premium spray polyurethane foam building insulation system. The product is generated on site by combining an isocyanate and a polymeric resin through a dual-component proportioner. Fast, easy and adaptable, it can achieve an R-value of 20 at 3 inches. Costarthermal B12 is a low density based polyurethane foam recommended for roofing and other exterior insulation because it is applied in a continuous manner, in addition to thermal resistance properties.