Abstract: A method of forming structural board panels from short strands of bagasse or other cellulistic material. The material resinated, compressed and cured to give an open structural block. A mortar screed of portland cement and sand is then applied to penetrate interstices between the strands and is built up with rendering and facing layers of mortar. A reinforcement, such as an open mesh net of resinated nylon strands may be incorporated in the facing layer.