RetroFoam’s foaming process uses two water-soluble components of a free-flowing powdered resin and an aqueous based foaming agent. Compressed air is used to generate a dense, 60% closed-cell foam which is physically coated with the water-soluble resin. The foaming agent reacts with the resin within 10-30 seconds, transforming the foam in to a rigid, plastic solid when dry. RetroFoam does not expand. This process is similar to the reaction of a two-part epoxy resin and produces a finished product that is inert, lightweight and non-flammable. Unlike resins used for conventional foamed-in place materials made from liquid formaldehyde and urea, RetroFoam’s kiln-dried polymer resins are complete and only require mixing with water to make consistent foam every time.