Section 256. Bulkheads and scuttles

1. Every required stair and fire-stair
  in  a  dwelling  three  stories  or more in height shall have a bulkhead
  constructed as provided for fireproof dwellings in section  two  hundred
  four.
    2. A dwelling which is two stories or less in height shall be provided
  at each required stair or fire-stair either with such bulkhead or with a
  scuttle  at least two feet by three feet in size, located in the ceiling
  of the public hall on  the  top  story.  Every  such  scuttle  shall  be
  arranged  to  be  readily  opened,  shall be covered on the outside with
  metal and shall be provided with stairs or  a  stationary  metal  ladder
  leading  thereto  and  easily  accessible  to  all  the occupants of the
  dwelling.
    3. When the roof of a dwelling is pitched or sloped more than  fifteen
  degrees,  no  bulkhead  or  scuttle, or stair or ladder leading thereto,
  shall be required.