Section 27-454. Roof storage of motor vehicles

Roofs of buildings shall not
  be used for the parking or storage of motor vehicles unless the building
  is of class I-A, I-B,  or  I-C  construction,  or  is  an  open  parking
  structure.    When  the  roof of a building is used for parking of motor
  vehicles, it shall be provided with a parapet  wall  or  guard  rail  at
  least  three  feet  six  inches  high, and with curbs or wheel guards of
  noncombustible materials of a least eight inches high. Such guards shall
  be substantially anchored to  prevent  any  vehicle  from  striking  the
  parapet   wall  or  guard  rail.  Guard  rails  shall  comply  with  the
  requirements for railings in subchapter nine of this chapter.