(a) All sidewalks hereafter improved by placing walks with a permanent surfacing on any public highway or street within the City shall be so improved by constructing walks with stone flagging or concrete, and in accordance with the specifications prescribed by the Director of Public Service, and shall be of the width prescribed by resolution of Council, or as directed by the Director where no such resolution has been passed. The sidewalk shall be so laid that the top surface shall be properly roughened, so that the same shall be prevented from becoming slippery when covered with moisture. The roughened finish shall be of such character as in the judgment of the Director will effectually prevent at any time the slippery condition of such walks.
(b) Any grading necessary between the walks as laid, and the curb line, or between the walks and the edge of the sidewalk space as herein established, shall be done at the time of laying the walks, so as to leave the sidewalk space at the grade hereinafter described.
(c) The sidewalks as improved shall coincide with the line described as follows: beginning at the curb line with the established curb grade as determined by the City Engineer; Thence extending to the street line at right angles to the curb line, with a rise of three- eighths (3/8) of an inch to the foot; provided, that at street intersections, where the grade of the intersecting street prevents compliance with the above provisions, the walk shall be laid under the direction and to the acceptance of the Commissioner of Engineering and Construction.