Abstract: A method of producing structural supports for use particularly in mining applications includes the use of a relatively rigid and cylindrical shell casing. The shell casing is separable along the plane parallel to its axis, has open ends and is closed about a fabric tube which is axially supported therein. The fabric tube is filled with pressurized liquid building materials such as concrete. Once filled within the casing, the pressure of the building material forces the liquid component thereof out of the tube laterally and through perforations provided in the shell casing to drain the liquid away from the building material in the tube. The casing and tube are of size such that the remaining building material, which will constitute a pillar, extends completely between the surfaces it is to separate and support.