Once the excavation is complete, the formwork for concrete footings is constructed. This stage is usually completed in less than a day. The footings should be cast either on undisturbed soil on roc or compacted granular material, rather than on topsoil or unstable ground.
The thickness and width of the soles can vary based on loads and the type of soil. In general, the base must extend at least 4 inches on each side of the foundation wall. It is advisable to install rebar when pouring steel soles, because the benefits far outweigh the costs. A joggle on the top of the footing can enhance the lateral strength of the foundations.