The present invention provides a rigid polyurethane foam comprising the reaction product, at an isocyanate index of from about 90 to about 400, of a polyisocyanate and a polyol component comprising, about 20 wt. % to about 80 wt. %, based on the weight of the polyol component, of a double metal cyanide (DMC)-catalyzed polyether polyol having a number average molecular weight of greater than about 1,000 Daltons (Da), about 80 wt. % to about 20 wt. %, based on the weight of the polyol component, of a sucrose-based polyol having a functionality of from about 2.5 to about 6 and a number average molecular weight of from about 350 Da to less than about 1,000 Da, and about 0 wt. % to about 40 wt. %, based on the weight of the polyol component, of a low molecular weight organic compound having a number average molecular weight of less than about 600 Da in the presence of water, polyvinylchloride (PVC) particles having a diameter of from about 0.1 microns to about 200 microns, glass beads having a diameter of from about 40 microns to about 400 microns, and about 1 wt. % to about 30 wt. %, based on the weight of the polyol component, of expanded graphite, optionally, in the presence of at least one of carbon dioxide, surfactants, flame retardants other than expanded graphite, crosslinking agents, pigments and catalysts, wherein the rigid polyurethane foam with a density of about 10 pcf to about 25 pcf has a heat sag measured at 102 mm overhang at 121.degree. C. and one hour of less than about 5 mm and an average after-glow time of less than about 35 seconds. The inventive rigid polyurethane foams exhibit improved burn properties and reduced after-glow while maintaining improved heat sag performance over commercial materials.