(a) Application. The provisions of this section shall not apply to mechanical means of demolition. (b) Demolition of walls and partitions. (1) The demolition of walls and partitions shall proceed in a systematic manner and all demolition work above each tier of floor beams shall be completed before any demolition work is performed on the supports of such floor beams. (2) Masonry shall not be loosened nor permitted to fall in such masses as to endanger the structural stability of any floor or structural