Section 27-334. Protective guards

Buildings that are more than twenty-two
  feet in height and have roofs that are flatter than  twenty  degrees  to
  the horizontal shall be provided with a parapet not less than three feet
  six  inches high, or be provided with a three foot six inch high railing
  or fence, or a combination of a  parapet  and  railing  or  fence  which
  together  are  not  less  than  three  feet six inches high. Railings or
  fences may be located inward from  the  face  of  the  exterior  wall  a
  distance  not  exceeding  six  feet,  and  shall  be of a type that will
  prevent children from crawling through or over  them.  Where  roofs  are
  used  for  recreational  purposes,  wire  fencing at least ten feet high
  shall be constructed. Where ball games are  played  on  roofs  the  wire
  fencing  shall  be  extended  to  provide an overhead closure. Except on
  buildings of class II-D or II-E construction, railings or  fences  shall
  be of noncombustible material. Railings shall be constructed as required
  in section 27-558 of article three of subchapter nine of this chapter.