Abstract: A method of pouring molten steel into a container having a bottom made of material subject to damage by the falling stream includes providing a light weight tin free steel mat made from a plurality of thin sheets each having closely spaced holes therein over most of its area and the sheets being arranged in a plurality of layers arranged to define a honeycombed spongelike structure of considerable thickness having a plurality of discontinuous voids. Substantially flat individual thin sheets are arranged on the top and bottom of the spongelike structure to form an assembly with the top and bottom sheets being made from tin free steel. None of the discontinuous voids extend from the top sheet to the bottom sheet. The mat is lowered into the container and positioned on the bottom after which the molten steel is poured onto the mat which protects the bottom while it melts and is absorbed into the molten steel.