An Orion-style dome uses spray-in-place fence technology to create an outer, semi-structural wall. The Airform membrane is attached to the top of this wall and the entire structure is pressurized — inflating the membrane.
Several inches of polyurethane foam is applied to the interior of the Orion wall and Airform membrane. Steel is hung from the foam and shotcrete is applied to the wall/dome structure. When finished the foam and concrete form a seamless, monolithic, shell.