Pad foundations tend to be the simplest and cheapest foundation type and are used when the soil is relatively strong or when the column loads are relatively light. They are usually square or rectangular on plan, of uniform thickness and generally of reinforced concrete. They can be stepped or haunched, if material costs outweigh labour costs.
The reinforcement can vary from nothing at one extreme through to a heavy steel grillage at the other, with lightly reinforced sections being the most common. Typical types are shown in Fig. 1.5.