Curbs must be built with all sidewalks and shall be at least fourteen inches deep and as much deeper as required to get a suitable foundation, six inches in width at the top, perpendicular at the back and batter out in front at the rate of one and one-half inches in one foot, and shall be rounded on the upper edges to a radius of one inch. The inside core of the curb shall be composed of concrete mixed as specified in this chapter for sidewalks and placed in forms so as to be up to within three-quarters of an inch of grade after tamping. The top layer of three-quarters of an inch shall be composed of cement and gravel as specified in this chapter for sidewalks. The top layer shall be finished and marked into blocks not to exceed six feet in length. After the concrete core has set sufficiently hard, the forms shall be removed and the front side of the curb shall be given a coat of plaster three-eighths of an inch in thickness, which shall be trowelled smooth or floated to an even surface and marked into blocks, to correspond with the markings in the top layer of the curb. (Ord. 12-03, 2012)