Structural Insulated Panels (SIP)

Structural insulated panels (SIP) are composite building materials, which are comprised of two layers of structural board with an insulating foam layer in between. The boards are often oriented strand board (OSB), and the foam is either polystyrene foam (EPS), extruded polystyrene foam (XPS), or polyurethane foam. Other materials may also be used including plywood, pressure-treated plywood, steel, aluminum, and cement panels. Exotic materials such as fiber-reinforced plastic, Magnesium Oxide, and stainless steel may also be used. Structural insulated panels are also available with cores made from agricultural fibers, such as wheat straw, which provide similar thermal and structural performance as the foam.