Description: In many parts of Britain, building sands complying with the relevant British Standards are unobtainable locally, and other sands are often used. This report describes an investigation into the current practice in using non-standard sands and the effect of these sands on the durability of rendering and brickwork. It was found that 5% of sands used for rendering and 59% of sands used in brick laying complied fully with the relevant Standard. Nevertheless, a survey of existing buildings in which non-standard sands were used showed that good durability was achieved provided the mix proportions were adequate. These results indicate that a revision of the requirements of the British Standards for building sands should result in the more economic use of natural resources without any significant fall in the quality of rendering and brickwork.