The board of local improvements shall designate someone to carefully inspect the entire work done pursuant to any such proceeding and contract, and the materials therefor, during the progress of the work, to the end that the contractor shall comply fully and adequately with all the provisions of the ordinance, and of the contract under which the work is to be done, and the specifications therefor. Upon the complaint of any property owner that the work or materials do not comply with those requirements, the president of the board of local improvements shall either examine the work and materials himself, or designate some member of the board to do so. The president of the board shall make a personal examination, and certify in writing as to the result thereof. This written certificate shall be filed with the papers pertaining to the board, and shall be open to public inspection at any time.