All labor and materials required for the construction of concrete foundations for monuments and markers shall be furnished by the city, upon required payment, to the city. No monument or marker shall be placed on a grave unless the concrete foundation is adequate to support the weight and size of the monument or marker as determined by the Cemetery Sexton. No monument or marker shall be larger than one and one-half feet wide or more than five feet in length unless otherwise waived by the Safety and Public Properties Committee for good cause shown.