17 Types of Footings The most common types of footings are: Spot Footings A spot or pad footing is used to support a single point of contact, such as under a pier or post. Spot footings are usually a 2' by 2' square pad, 10" to 12" thick, and made with reinforced concrete. Continuous Spread Footing A continuous spread footing is mainly used to provide a stable base around the perimeter of a building. Spread footings are often augmented with interior spot footings. The spread footing supports the weight of the exterior or foundation walls. The thickness of the footing provides the necessary strength for that support. The wide width of the footing base provides a large area with which to transfer the weight from the walls to the ground. This is key to preventing settling. Grade Beam Footing A grade beam footing is a continuous reinforced-concrete mem- brane used to support loads with minimal bending. Grade beams Bevelled exterior edges or uneven surfaces can require major modifica- tion to the greenhouse or foundation itself. The foundation must be level and square for the entire area where the greenhouse frame and interior support channels rest. construction tip