Can STYROFOAM* extruded polystyrene insulation be left exposed either inside or outside?
Building codes require that STYROFOAM* Brand Insulation be protected from the interior side of a wall or roof system by a 15-minute thermal barrier such as gypsum board. STYROFOAM XPS Insulations can be left exposed in residential crawl spaces and attics when these spaces meet certain requirements such as being separated from the rest of the residence and being free of any mechanical heat producing appliances such as a furnace or water heater.
