Structural insulated panel

A structural insulated panel, or structural insulating panel, (SIP), is a form of sandwich panel used as a building material in the construction industry. SIP is a sandwich structured composite, consisting of an insulating layer of rigid core sandwiched between two layers of structural board. The board can be sheet metal, fibre cement, magnesium oxide board (MgO), plywood or oriented strand board (OSB), and the core can either be expanded polystyrene foam (EPS), extruded polystyrene foam (XPS), polyisocyanurate foam, polyurethane foam, or be composite honeycomb (HSC). The sheathing accepts all tensile forces while the core material has to withstand only some compressive as well as shear forces. In a SIP several components of conventional building, such as studs and joists, insulation, vapor barrier and air barrier can be combined. The panel can be used for many different applications, such as exterior wall, roof, floor and foundation systems. Although foam-core panels gained attention in the 1970s, the idea of using stress-skinned panels for construction began in the 1930s. Research and testing of the technology was done primarily by Forest Products Laboratory (FPL) in Madison, Wisconsin, as part of a U.S. Forest Service attempt to conserve forest resources. In 1937, a small stressed-skin house was constructed and garnered enough attention to bring in First Lady Eleanor Roosevelt to dedicate the house. In a testament to the durability of such panel structures, it endured the Wisconsin climate and was used by University of Wisconsin–Madison as a daycare center until the early 2000s, when it was removed to make way for a new Pharmacy School building.