The principles of operation, basis for design and assumed design loadings for two types of reinforced concrete cement storage silo are descriptionbed. The Internal pressure loadings assumed for the design of the silos are compared with pressures measured on the walls in situ. The types of silo descriptionbed are the IBAU central cone silo and the Ouocell concentric silo. The IBAU silos specifically referred to were built at the Pretoria Portland Cement Company's Jupiter works in Germiston and the Duocell silos at the Blue Circle Cement Company's Uchtenburg works. The comparison of design and measured pressure loadings shows that current design codes may be extremely conservative. Design codes assume safe materials properties that may be considerably different from those of the material actually stored when the silo is functional. Economics can be effected if the properties of the material to be stored can be accurately and reliably determined at the design stage.