Winter Panel has made available its Structurewall insulated panels in an 8 1/4-inch-thick option that features an R-50 urethane-foam core. Structurewall panels, which also are available in an R-25, 4 1/2-inch thickness and R-38, 6 1/2-inch thickness, can be used as a substitute for 2- by 4-inch and 2- by 6-inch framing. The panels can span up to 8 feet in roof applications, saving the cost of additional support members.