The invention relates to thermoinsulating moldings containing porous, inorganic thermoinsulating materials and having an organopolysiloxane coating thereon, in which an uncoated thermoinsulating molding is coated with a diorganopolysiloxane containing rod-shaped styrene-(meth)acrylate copolymers which are obtained from a free radical copolymerization of styrene and (meth)acrylate in the presence of the diorganopolysiloxane.