(A) All walks four feet wide shall have contraction or dummy joints spaced at no more than five feet center to center along the sidewalk center line. Walks of other widths shall be cut into sections of such lengths as directed by the engineer.
(B) The depth of all contraction or dummy joints shall be one-third the thickness of the finished walk. The contraction joints and edges of the separate slabs of walk shall be finished with an edging tool with a one-half-inch radius.