2006 New York Code - Bulkheads.

 
    §  204. Bulkheads. Every stair and fire-stair required by this chapter
  to extend to the level of  the  roof  shall  extend  to  and  through  a
  fireproof  bulkhead  or  other  fireproof  enclosure  in such roof. Such
  bulkhead or enclosure shall give unobstructed access  at  all  times  to
  such  roof  by means of a fireproof door and door assembly with the door
  self-closing. Stairs to a bulkhead or enclosure shall have  a  handrail.
  Where  the  roof  of  a  dwelling is pitched or sloped more than fifteen
  degrees, no bulkhead or stairs leading thereto shall be required.