ABSTRACT
The movement of clay soils due to moisture changes, was mentioned in Sheet No. 12. The effect is most marked towards the outer periphery of the foundation and the movement of the clay may cause the foundation slab to tilt and the wall to crack. Fig 1. The volume changes become less with depth and below 0.9m the movement is so slight that it will not seriously effect foundations. Thus the minimum depth of normal strip foundations is 0.9m.
