Structural insulated panel

SIPs are most commonly made of OSB panels sandwiched around a foam core made of polystyrene.

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.