Made with OSB sandwiching an EPS core, the Insulspan SIP System comes pre-cut and ready to install as walls, floors, and roofs. A 6?1/2-inch wall panel offers a nominal R-value of 21.1; a 101/4-inch roof panel provides a nominal R-value of 35.1. The company offers special-order SIPs using FSC-certified OSB.517.486.4844.