Chapter 9- Provisions for structural safety, natural disaster, fire and building services Section-9.3.1 Fire Escape Staircase

This section outlines the general requirements for fire escape staircase into various buildings which are as follows:
a. Fire Escape will be an additional external stair case and shall not to be taken in to account for calculating the evacuation of the occupants of a specific floor. It shall not be inclined at an angle greater than 450 from the horizontal.
b. All fire escapes shall be continuous from ground to terrace.
c. Entrance to fire escape shall be separate and remote from the internal staircase.
d. The route and enclosure to fire escape shall be free of obstructions at all times, except
a doorway leading to the fire escape which shall have the required fire resistance.
(refer NBC Part 4)
e. Fire escape shall be constructed of non-combustible materials of required fire
resistance (refer NBC Part 4). Unprotected steel frame staircase will not be accepted as fire escape.
f. Handrails shall be of a height not less than 1.0 m and not exceeding 1.2 m.
g. Scissors staircase can also be used as fire escape subject to the condition that the two entrances to the scissors staircase are not less than 9.0 m apart.
h. In case the provision is for a single staircase, the same shall be separated at the ground floor level to have an access to the basement (if provided).
i. The staircase enclosure if on external wall of the building shall be ventilated to
atmosphere at each landing or in case it is in the core of the building it shall be
maintained at a positive pressure as mentioned in NBC part IV, Fire and Life Safety, with both automatic and manual operation facilities and fire alarm systems.
j. Fire escape staircases shall have straight flight not less than 1.35 m wide with 25 cm treads and risers not more than 19 cm. The number of risers shall be limited to 15 per flight.
k. Spiral stairs can be used subject to, the use of spiral staircase shall be limited to low occupant load and to a building of height 9.0 m. further a spiral fire escape shall not be less than 1.5 m in diameter and shall be designed to adequate head room. "