All persons engaged in the construction or repairing of sidewalks shall construct and maintain a temporary sidewalk in the street, which temporary sidewalk shall be of planks not less than two inches (2") thick, and shall not be less than three feet (3') in width, and shall extend from sidewalk to sidewalk around such sections of sidewalk in course of construction or repair, and such temporary sidewalk shall be constructed before any work whatever is commenced on the permanent walk and must not be removed until such permanent sidewalk is open to traffic. (Ord. 97, 8-5-1910)