(post #103929, reply #7 of 8) The required footing width depends on what your local code says but there is normally a requirement for minimum width and for minimum projection. Projection is how much footing concrete sticks out beyond the foundation wall - both inside and outside the foundation and it might be 2 or 4. Also, minimum footing width and thickness is dependent of the # of stories of the building and the bearing capacity of the soil.