Sign maintenance. Signs shall be constructed of durable materials, maintained in good condition, and not allowed to become dilapidated. All signs, together with all supports, braces, anchors, and other parts, shall be kept in continual repair, including cleaning, painting, replacing of defective parts, and otherwise maintaining a presentable condition. Lack of proper maintenance shall be considered abandonment, and the sign shall be repaired, painted, cleaned, or otherwise returned to a presentable condition or removed within 10 days upon notification by the Zoning Officer or Construction Code Official.