abbr. closed-cell spray polyurethane foam
A type of spray polyurethane foam expanded with non-reactive blowing agents to yield a rigid cellular structure. It has a density between 1.5 and 2.5 lb. per cubic foot and a nominal thermal resistance of R-6.5 per inch (this will vary from manufacturer-to-manufacturer).
- medium-density SPF, closed-cell SPF, two-pound foam (a reference to ccSPF’s typical density of 2 lb. per cubic foot)