For most applications, SIPs are structurally self-sufficient. The structural characteristics of SIPs are similar to that of a steel I-Beam. The OSB skins act as the flange of the I-beam, while the rigid foam core provides the web. This design is extremely strong and eliminates the need for additional framing.
In cases where a point load from a beam or header requires additional support, a double dimensional lumber spline or engineered wood spline is field installed at in-plane panel connections.
SIPs are also used as curtain walls for steel frame or timber frame structures. In large commercial applications SIPs can minimize the amount of structural support needed and reduce material costs.
In roof applications, SIPs rely on beams and purlins for support. SIPs can span long distances, allowing a minimal amount of structural supports to be used.