Usually when someone says they’re “going gray,” it’s a gentle way to indicate they’re getting older. But in the case of structural insulated panels, when you see gray insulating foam cores on the job site, it means a new advance in the panels.
Manufacturers have produced SIPs using a variety of foam insulation cores, including expanded polystyrene (EPS), extruded polystyrene (XPS), polyisocyanurate (Iso) and polyurethane (PUR)—with EPS being the most common. Now, a new type of insulation enters the mix of options—graphite polystyrene (GPS).