§ 60. Bulkheads and scuttles. 1. There shall be a fire-resistive bulkhead in the roof over, or connecting directly by means of a public hall with the highest portion of every stair extending to the highest story below the main roof. Stairs leading to such bulkheads shall be fire-retarded as required for other public stairs and shall have at the top fireproof doors and assemblies with the doors self-closing. All stairs to required bulkheads shall be provided with a guide or handrail. A scuttle so constructed as to be readily opened may be substituted for a bulkhead in dwellings not exceeding three stories and a basement in height. Such scuttle shall be at least twenty-one inches in width and twenty-eight inches in length, covered on the outside with metal and provided with a stationary iron or steel ladder leading thereto.

2. 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.

3. A bulkhead door or scuttle shall never be locked with a key, but may be fastened on the inside with movable rustproof bolts or hooks. All key locks shall be removed.

4. Bulkheads and stairs leading thereto existing on July first, nineteen hundred fifty-two, shall be permitted provided the stairs have such angle of ascent and treads of such dimensions as may be approved by the department.