Modern Construction Techniques in civil engineering, Fire Safety

1. Modern Construction Techniques
Zishan Raza Khan

23. FIRE PROTECTION REQUIREMENTS FOR HIGH RISE
BUILDINGS- 15 M IN HEIGHT OR ABOVE
• Construction
C-1.1. All materials of construction in load bearing
elements, stairways, corridors and facades shall
be non-combustible.
C-1.2. The interior finish materials shall not have a
flame spreadability rating exceeding class 1
C-1.3. The internal wall of staircase shall be of brick
or reinforced concrete with a minimum of 2hr.
Fire rating.
C-1.4. The staircase shall be ventilated to the
atmosphere at each landing with a vent at the
top; the vent opening shall be of 0.5 m2 in the
external wall and the top. If the staircase cannot
be ventilated, because of location or other
reasons, a positive pressure 50Pa shall be
maintained inside. The mechanism for
pressurising the staircase shall operate
automatically with the fire alarm. The roof of
the shaft shall be 1m above the surrounding
roof. Glazing or glass bricks if used in staircase
shall have fire resistance rating of minimum 2
hours.
C-1 .5. Lifts
General requirements of lift shall be as follows:
(a) Walls of lift shaft enclosures shall have a fire
rating of 2 h ;lift shafts shall have a vent at the
top, of area not less than 0.2 m2;
(b) Lift motor room shall be located preferably at the
top of the shaft and separated from the shaft by
the floor of the room;
(c) Landing doors in lift enclosures shall have fire
resistance of not less than 1h;
(d) The number of lifts in one row for a lift bank shall
not exceed 4 and the total number of lifts in the
bank shall not exceed 8. A wall of 2 h. rating
shall separate individual shafs in a bank.
(e) Lift car door shall have a fire resistance rating of
half an hour;
(f) Collapsible gates shall not be permitted for lifts.
They shall have solid doors with fire resistance
of at least Ih.;
(g) If the lift shaft and lobby is in the core of the
building, a positive pressure between 25 and 30
Pa shall be maintained in the lobby, and a
positive pressure of 50 Pa shall be maintained in
the shaft. The mechanism for pressurisation
shall act automatically with the fire alarm; it
shall be possible to operate this mechanically