Siporex is lightweight autoclaved aerated concrete which is completely cured, inert and stable form of calcium silicate hydrate. It is a structural material, approximately one quarter the weight of conventional concrete, composed of minute cells which give the material light weight and high thermal insulation properties. It is available as blocks and pre-cast reinforced units, i.e. floors, roofs, walls and lintels. It has the following advantages: Light weight Excellent thermal insulation Workability Fire resistance Dimensional accuracy and stability Speed of erection Reduction in labor Factory quality control Siporex has been used on large scale projects such as schools, hospitals and housing projects, under all climatic conditions since the early nineteen thirties.