InsulBloc® is a 2.0 lb./cu ft density, closed-cell spray polyurethane foam that provides higher R-value per unit thickness than can be achieved with any other type of commercially available insulation. SPF is produced when the two chemicals polyol and an isocyanate are mixed together in the presence of catalysts and other additives using a specially made spray applicator system. The chemicals, sprayed as a liquid, react, expand, and cure in place, forming a seamless insulating and damp-proofing membrane.