All fences shall be maintained in a safe, sound and upright condition. If the Building Inspector or Zoning Officer, upon inspection, determines that any fence, or portion of any fence, is not being maintained in a safe, sound or upright condition, he shall notify the owner of such fence in writing of his findings and state briefly the reasons for such findings and order such fence or portion of such fence repaired or removed within 30 days of the date of the written notice.