The present invention is directed to a rigid, molded foam produced by reacting: a) one or more organic polyisocyanates, with b) a polyol blend comprising i) 100 parts by weight of a mixture comprising: 1) from 30 to 80 parts by weight of one or more polyethers having hydroxy functionalities of 2 or 3 and molecular weights of from about 1,000 to about 8,000, the polyethers further being characterized as containing no nitrogen atoms and not being filled polyethers, 2) from 10 to 50 parts by weight of one or more adducts of toluene diamine and an alkylene oxide, the adduct having a molecular weight of from about 350 to about 700, 3) from 0 to 15 parts by weight of one or more di- or trialkanol amines, with the amounts of components 1), 2) and 3) totaling 100 parts, and c) from about 0.1 to about 4 parts by weight per 100 parts by weight of component b) of a silicone cell-opening surfactant and d) from 1 to 7 parts by weight of water, and e) from 0.1 to 2 parts by weight of at least one tertiary amine catalyst; wherein the reaction mixture contains no auxiliary blowing agents and wherein the amount of polyisocyanate is such that the isocyanate index is from 95 to 120.