The complete line of JM open- and closed-cell spray foam insulation solutions provide superior thermal and energy performance, as well as advanced air, moisture and sound control in any climate. These products can be used in interior and exterior walls, unvented and vented attics, floors, ceilings and crawl spaces. Plus, using spray foam can reduce air leaks and create a more comfortable, energy-efficient home – meaning you could see more energy savings every month.

JM Corbond® Open-Cell Appendix X Spray Foam is a lower-density, nonstructural foam that offers most of the thermal performance and installation benefits of closed-cell spray foam at a lower cost. It provides an exceptional air and sound barrier as well as R-value, and meets AC 377 NFPA 286 Appendix X requirements for application without an ignition barrier in attics and crawl spaces.
These coatings are emulsified asphalt and consist of asphalt particles dispersed in water; they utilize clay as the emulsifying component. These coatings also contain many types of organic and/or inorganic fibers and fillers to provide extra strength to the coating. These coatings are available in black, brown, or as a reflective coating when titanium dioxide or aluminum pigments are added.
Polyurethane is a closed-cell foam insulation material that initially contains a low-conductivity gas in its cells.[5] As a result of the high thermal resistance of the gas, spray polyurethane insulation typically has an initial R-value around R-3.4 to R-6.7 per inch.[5] In comparison, blown fiberglass typically has an R-Value of only R-3 to R-4 per inch.[6]
A. You can use closed-cell spray foam that way if you want, although you should realize that the spray foam will prevent the roof sheathing from drying inward. This approach should only be used if the roof sheathing is bone dry, because it will never dry when sandwiched in this manner. Most building scientists would prefer to see fiberglass rather than closed-cell spray foam under the roof sheathing in this type of assembly.

Roof Coating Seal