So, for example, a 32-inch-wide footing under an 8-inch wall would need to be at least 12 inches thick. Instead, however, you could reinforce the footing with transverse steel (running in the crosswise direction, not along the footing).In most residential situations, #4 rod at 12 inches o.c. will be plenty for 8-inch-thick footings up to 4 feet wide.The steel should be placed about 3 inches up from the bottom of the footing.n most residential situations, #4 rod at 12 inches o.c. will be plenty for 8-inch-thick footings up to 4 feet wide. The steel should be placed about 3 inches up from the bottom of the footing.