§ 147. Bulkheads and scuttles. 1. Except as otherwise provided in
subdivision two of this section, every required stair, fire-stair and
fire-tower in dwellings three stories or more in height shall have a
bulkhead constructed as provided for fireproof dwellings in section one
hundred four, except that the bulkhead of any required stair which is
not required to be fireproof may be built of wood covered on the outside
with twenty-six gauge metal and on the inside with wire or metal lath
covered with two coats of cement plaster or other fire-retarding
material approved by the department.

2. Such a dwelling which is two stories or less in height, or is three
stories in height and erected pursuant to plans filed with the
department on or after May first, nineteen hundred fifty-nine and
occupied by not more than one family on each story, shall be provided at
each required stair, fire-stair or fire-tower either with such a
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 and so
arranged as to provide direct and uninterrupted access to the roof.
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 iron ladder or ladders leading thereto and easily accessible
to all the tenants of the dwelling.

3. No bulkhead or other superstructure on the roof shall be used for
human occupancy.

4. When a dwelling has a pitched or sloping roof with a pitch or slope
of more than fifteen degrees, no bulkhead or scuttle or stair or ladder
leading thereto shall be required.