A protected shaft shall not be used for any purpose additional to those given as defined under Cl.1.4.67. All services such as, pipe/ duct installation shall not be located inside a protected staircase, unless otherwise permitted in Cl.3.8.7. Likewise, no washroom is allowed to be located inside protected staircase.

Every protected shaft shall be required to:

a. Form a complete barrier to fire between the different compartments which the shaft connects, and

b. Have the appropriate fire resistance to comply with the requirements of Cl.3.3, and

c. Be constructed of non-combustible material (together with any beam or column which forms part of the enclosure and any structure which carries it).

a. A protected shaft shall have no openings in its enclosure, except:

(1) In the case of any part of the enclosure which is formed by a separating wall, any opening which complies with the requirements of Cl.3.6 for separating walls, or

(2) In the case of any part of the enclosure which is formed by a compartment wall or a compartment floor, any opening which complies with the requirements of Cl.3.7 for compartment wall or compartment floor, or

(3) In the case of any part of the enclosure which is formed by the protecting structure:

(a) a door which has the appropriate fire resistance to comply with the requirements of Cl.3.4 for test of fire resistance, or otherwise permitted by provision of Cl.3.8.6, or

(b) the passage of a pipe, or

(c) inlets to and outlets from and opening for the duct if the shaft contains or serves as a ventilation duct.

b. Such openings in the protected shaft shall be protected to comply with the relevant provisions of Cl.3.9 for protection of openings.

Every protecting structure shall be constructed wholly of non-combustible materials.

A protected shaft used for the passage of people, such as exit staircases, shall be ventilated to comply with the relevant provisions of the Code.

a. Any door fitted to an opening in protecting structure shall have fire resistance for not less than half the period required by other provisions of the Code for the protecting structure surrounding the opening.

b. Any door fitted to an opening in protecting structure of a shaft containing services, such as electrical and telecommunication cables, pipes (including gas pipe in separate shaft), ducts etc., is not required to comply with the requirements in Cl.2.2.17e.(2) if it is fitted with a self-closing device. Rising mains and hose reel doors shall not be fitted with self-closing device and shall comply with the stipulated corridor width when the door is in its fully opened position. Areas within the swing paths of the rising mains and hose reel doors shall be clear of any obstruction/ storage at all times.

c. Exception

Any door fitted to an opening in protecting structure of a shaft containing services such as electrical cables, pipes (including gas pipe in separate shaft), ducts, etc., is not required to have the fire resistance rating if the door is located along the wall facing the external corridor.

A protected shaft which contains an exit staircase shall comply with the following:

a. It shall not contain any pipe conveying gas or combustible liquid.

b. It shall not contain any services that are not solely serving the same exit staircase except for:

(1) Sprinkler pipe, rising mains, hose reel pipe, fire alarm system cable in metal conduit, metal water supply pipe not exceeding 50mm in diameter and water tap; and

(2) UPVC or cast iron rain water down-pipes serving the roof directly above the exit staircase, and not routed through anywhere outside the staircase.

(3) Telecommunication cables, e.g. leaky coaxial cables (LCX) and one-way emergency voice communication system cables.

c. The protecting structure shall be constructed of masonry or drywall. If drywall construction is used, all of the following conditions shall be complied with:

(1) The drywall shall be non-combustible.

(2) The drywall shall have the requisite fire resistance rating at least equal to that of elements of structure;

(3) The drywall shall in terms of impact & deflection performance to meet the partition grade under BS 9999 (Test for partitions) in accordance with BS 5234-2;

(4) The drywall shall meet the criteria, in terms of water absorption and bending strength performance, when subject to test of BS 1230 Part 1 (for gypsum plaster board) or ISO 1896 (for calcium silicate or cement board); and

(5) The station shall have at least two independent exit staircase shafts (scissors exit staircases are considered single shaft).

A protected shaft which contains a lift shall comply with the following:

a. It shall not contain any pipe conveying gas or combustible liquid, other than those in the mechanism of a hydraulic lift.

b. The protecting structure shall be constructed of masonry or drywall. If drywall construction is used, the following conditions stipulated underCl.3.8.7c.(1) to (4) shall be complied with. The drywall shall also meet the criteria of cyclic loading and dynamic test as specified under Cl.3.3 of National Construction Code of Australia C 1.8.

c. The lift shall be considered as not enclosed within a protected shaft where a lift is:

(1) located at the edge of atrium floors, or

(2) at the external wall and outside the station, or

(3) located in the public area which serves not more than three storeys within the same compartment.

d. The protected shaft shall be vented in accordance with SS 550. The vents shall be so arranged as to induce exhaust ventilation of the shaft. Where vents could not be provided because of the location of the lift shaft, ventilation duct protected by drywall complying with Cl.3.8.8b. serving as ventilation of the shaft can be provided in accordance with Chapter 6.

e. Openings for the passage of lift cables from the lift shaft into the lift motor room shall be as small as practicable.

f. Transom panel above lift entrance shall not be considered as part of the entrance and shall therefore conform to the fire resistance requirements of the protected structure.

g. If it serves any basement storey and not adjoining any void connecting to upper levels or any external spaces, there shall be provided a lobby enclosed by walls having fire resistance of at least 1-hr and fire door of at least ½ hour.

Exception: The requirement for lobbies shall not apply where lift is located in the public areas which serves not more than three basement storeys within the same compartment.

A protected shaft used for the enclosure of services shall comply with the following:

a. The protecting structure for protected shaft containing mechanical ventilation ducts serving exit staircases, exit passageways, smoke-free, and fire lift lobbies which pass through one or more floors shall be constructed of masonry or drywall. Such shaft shall be completely compartmented from the rest of the shaft space containing other ducts or any other services installations. A protected shaft containing ducts serving other areas which pass through floor slabs can be constructed of drywall. If the protected shaft is of drywall construction, the conditions stipulated in Cl.3.8.7c. shall be complied with.

b. Cavity barriers

A protected shaft used for the enclosure of electrical power services shall be interrupted at every floor level with at least ½-hr fire resistance cavity barriers. Protected shaft used for the enclosure of telecommunications services shall be interrupted by at least ½-hr fire resistance cavity barriers at vertical intervals not exceeding 15m. The cavity barriers within trunking enclosing electrical and telecommunication cables can be exempted if the following conditions are met:

(1) the cables shall be flame retardant type complying with IEC 60332;

(2) the floor within the shaft shall be sloped upward with an angle of at least 45° to the floor level; and

(3) the fire doors to the protected shaft are installed with self-closing devices.

c. Self-closing devices

Automatic self-closing devices are not required to be installed on fire resisting doors opening into protected shafts which are interrupted by at least ½-hr fire resistance cavity barriers at every floor level, or protected shafts containing sanitary pipes or water pipes, provided that the fire resisting doors are kept closed and locked at all times.

d. Fire resistant cables, flame retardant cables and extra low voltage telecommunication cables need not be housed in protected shafts.