Cementitious insulation material is a cement-based foam used as sprayed-foam or foamed-in-placed insulation.
One type of cementitious, spray-foam insulation is known as Air-Krete™. It contains magnesium silicate and has an R-value of about 3.9 per inch. With an initial consistency similar to shaving cream, Air-Krete™ is pumped into closed cavities. After curing, it's similar to a thick pudding.
Cementitious foam costs about as much as polyurethane foam. It's also nontoxic and nonflammable. Cementitious foam is made from minerals (like magnesium oxide) extracted from seawater.
Article source: The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE). For the most up-to-date information please visit the EERE website.