I will be pouring a 3x3 concrete pad, 5" thick. The pad is thick since Section of It will probably be slightly higher than ground. The pad will probably be a landing for a ramp. The ramp will "land" or rest about eight" from the sting on the pad. http://concretedobies27923.designi1.com/17811467/how-to-use-dobie-blocks-an-overview