Dimension of a strip foundations

cavity wall, internal load bearing wall
min 150 mm thick strip concrete foundation
thickness of the foundation should be equal to p or 150 ,, , whichever is greater.
wall should be central on foundation

1. Dimension of strip foundations
2. If the thickness of a concrete strip foundation (without steel reinforcement ) were less than its projection each side of a wall , the concrete might fail through the weight of the wall causing 45 degree shear crack
3. If this occured , the bearing surface of the foundation on the ground would be reduced to less than that necessary for stability
4. Where the load is place directly on top of the concrete foundation and compressed between the ground , the foundaton remains stable . However , the concrete outside the 45 degree angle experience some tension as the reaction of the ground attempts to lever the foundation upwards , this the foundation would fail.