59 - Ventilation for shafts.

§  59.  Ventilation for shafts. 1. There shall be provided in the roof  directly over each stair, fire-stair, dumbwaiter,  elevator  or  similar  shaft  which  extends  to  or  within one story of a roof, a ventilating  metal skylight of the cross-sectional area of such shaft. Such  skylight  need  not, however, exceed twenty square feet in area. Where an existing  skylight is smaller than the  dimensions  or  area  prescribed  in  this  subdivision,  no  structural change shall be required, but a ventilating  metal skylight fitting  the  existing  opening  in  the  roof  shall  be  sufficient.  Every skylight shall be glazed with plain glass in the roof  of such skylight and shall be equipped with metal screens over and under  the skylight. In lieu of a skylight a window of the same area at the top  story shall be accepted.    2.  Whenever  there  is a flooring of solid construction at the top of  any enclosed stair, fire-stair,  elevator  or  similar  shaft,  openings  shall  be left near the top of such shaft for ventilation. Such openings  shall provide  at  least  two  hundred  eighty-eight  square  inches  of  unobstructed  ventilation  and shall communicate directly with the outer  air, or be otherwise ventilated in accordance with the provisions of the  local building code.    3. It  shall  be  unlawful  to  discharge  into  any  such  shaft  any  inflammable  or  volatile  gases, liquids or other thing or matter which  would endanger life.