I am building an addition on the back of my house. The foundation for this addition is deeper in the ground than the existing house by about
18 inches. I need a retaining wall along bottom of the existing foundation to keep it supported and to hide/seal off the loose soil. I plan to use a concrete block retaining wall which will run 20 feet long and 2 feet high. Do I need to create an eight-inch footing to support this small retaining wall? Or, can I just get the four-inch concrete floor poured in the new foundation area and then build the retaining wall on that?Thanks Kathy