3.7.1 Requirements of compartment walls or compartment floors
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Explanations & Illustrations
Clause 3.7.1 : Requirements of compartment walls
or compartment floors
Section
Figure 3.7.1
The provision of compartment floor would apply to separate basement from upper storeys in the case where the building has 4 or more upper storeys or levels and a basement. Under such situation, Cl.3.2.5d. shall be complied with i.e. the compartmentation between basement and 1st storey shall not be penetrated by any openings or services even if:
a. such openings are provided with fire doors; and
b. the services are in protected shafts.
Compartment walls and floors are to be totally imperforate except for the following permitted openings:
a. doors
b. protected shafts
c. ventilation ducts
d. pipes
e. chutes e.g. refuse, linen
Compartment walls and floors are to be constructed wholly of non-combustible materials, including any beam or column which forms part of the wall or floor and any structure which it carries. The walls and floors shall be constructed to have the necessary
fire resistance of min. 1 hour to comply with the requirements of Cl.3.3. See Cl.3.2.5 on the provision of compartment walls and floors to apartment/maisonette unit. Provision of fire resisting glass in compartment wall or floor separating residential units is not allowed.
Every compartment wall or compartment floor shall be required to:
a. form a complete barrier to fire between the compartments it separates;
b. have the appropriate fire resistance to comply with the requirements of Cl.3.3, except for compartment which is abutting a common
circulation space and not more than 3m from the eaves of the building;
c. be constructed of non-combustible materials (together with any beam or column which forms part of the wall or floor, and any structure which it carries); and
d. shall not have fire-resisting glass components, unless permitted under Cl.3.15.14.
3.7.2 Openings in compartment wall or compartment floor
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Explanations & Illustrations
Clause 3.7.2 : Openings in compartment wall or compartment floor
Figure 3.7.2 - 1 : Door opening in compartment wall
Section
Figure 3.7.2 - 2 : Protected shaft opening in compartment floor
Figure 3.7.2 - 3 : Fire damper opening in compartment wall
Section
Figure 3.7.2 - 4 : Pipe penetration in compartment wall
It is a common practice to provide ½-hr fire resistance entrance door to flat or maisonette from common space, e.g. lobby. The fundamental reasons are that entrance doors are subject to normal everyday usage and that it is generally accepted that
no combustible materials would be placed behind the doors.
In other situation, the door within compartment wall shall have the same fire resistance as the compartment wall. This is applicable to trap doors in floors.
Compartment walls and floors are required to be totally imperforate except for the above mentioned openings to permit movement of people, air, services etc. in the building.
Other provisions in the code which allow fire door to have ½ the fire resistance rating of the adjoining compartment wall are:
a. doors to protecting structure under Cl.3.8.6;
b. exit doors opening into an internal and external exit passageway under Cl.2.3.2b.(3) and Cl.2.3.2c.(2) respectively; and
c. exit doors opening into protected lobby under Cl.2.2.13b..
Doors to protected shafts are required to have ½ the period of the fire resistance rating of the protecting structure surrounding the opening. The main reasons for the above relaxation are:
a. Exit doors if required to have the same period of fire resistance rating as the surrounding wall would be quite heavy. Occupants escaping into the protected staircase would need to push hard to open the doors. Besides having to overcome the weight
of the doors, additional force would be required to deal with the self-closing device fitted to the doors and in certain cases, the force imposed by the staircase pressurisation system. This would slow down the evacuation process;
b. A fire that breaks into the shaft at one level would need to break out again at another level. The aggregate rating of the 2 doors, each at different level, would be considered as acceptable.
c. Door openings in protecting structures would be limited in size, hence the potential source of weakness in the overall integrity of the shaft is limited.
In other situation, the door within compartment wall shall have the same fire resistance as the compartment wall. This is applicable to trap doors in floors.
A compartment wall or compartment floor shall have no openings in it, except for
a. a door which has the same fire resistance rating as the compartment wall and complies with the relevant requirements of Cl.3.4, unless
permitted by other provisions of the Code, or
b. a protected shaft which complies with the requirements of Cl.3.8, or
c. the passage of a pipe or ventilation duct.
Such openings in the compartment wall or compartment floor shall be protected to comply with the relevant provisions of Cl.3.9.
a. Junction with other structures
Where a compartment wall or compartment floor forms a junction with any structure comprising any other compartment wall, or any external wall, separating wall or structure enclosing a protected shaft, such structures shall be bonded together at the junctions
or the junctions shall be fire-stopped to comply with the requirements of Cl.3.12.
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Explanations & Illustrations
Clause 3.7.3a. : Openings
Section
Figure 3.7.3a.
b. Opening in curtain walling
The opening occurring at the junction between the edge of a structural floor and the curtain walling shall be sealed to prevent the spread of smoke and flame from the lower floor to the upper floor via the opening. Materials to be used for sealing the opening shall have the requisite fire resistance rating as the elements of structure.
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Explanations & Illustrations
Clause 3.7.3b. : Openings
Figure 3.7.3b. - 1 : Details at junction of curtain walling at floor
Figure 3.7.3b. - 2
3.7.4 Compartment wall - roof junctions
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Explanations & Illustrations
Clause 3.7.4. : Compartment wall - roof junction
Section
Figure 3.7.4 - 1
Compartment wall is carried right up above the roof coverings to act as a barrier to prevent fire spread over the roof level. The above clause addresses the concern at the junction of compartment walls with roofs and other elements of structure to prevent
fire spreading through cracks and gaps at such junctions.
Axonometric view
Figure 3.7.4 - 2
Compartment wall shall be brought up to the underside of the roof coverings, including jack roof to complete the fire separation and to prevent fire spread from compartment to compartment. See also Cl.3.6.3 (separating wall – roof junction)
Where a compartment wall forms a junction with a roof, such compartment wall shall be extended up to form a close joint with the underside of the roof and shall be properly fire-stopped or shall be extended up above the level of the roof covering and the junction between such compartment wall and roof shall be properly fire-stopped so as not to render ineffective the resistance of such compartment wall to the effects of the spread of fire.
3.7.5 Prohibition of combustible materials
No combustible material shall be built into, extended through or extended across the ends of any compartment wall or compartment floor or extended over the top of any compartment wall in such a manner as to render ineffective the resistance of such wall or floor to the effects of the spread of fire.
3.7.6 Non-combustibility of compartment walls or floors
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Explanations & Illustrations
Clause 3.7.6 : Non-combustibility of compartment walls or floors
( No illustration )
Construction of compartment walls and floors is to be entirely of non-combustible material, except for compartment walls or floors in buildings which are required to be retained by URA under the conservation programme. The exemption was an understanding
between the SCDF and URA. As a general guide, QPs are required to seek prior consultation with the SCDF before making BP submission. There are also certain other exceptions:
a. floor finishes
b. wall or ceiling linings complying with Cl.3.13
c. suspended ceilings under Cl.3.3.6
Any structural members carrying compartment walls or floors must also comply with the requirement of non-combustibility. Apart from the contribution made by suspended ceilings under Cl.3.3.6, the fire resistance of the structural members must be attained without assistance from any combustible material (with the exception of buildings designated for conservation).
Every compartment wall or compartment floor shall be constructed of non-combustible materials, unless permitted by the SCDF.
3.7.7 Use of fire shutter
a. General
A fire shutter is permitted to be used as compartment wall, except for the fire compartmentation to comply with the requirements of Cl.3.2.4b., Fire Command Centre (FCC) and means of escape, which include exit staircases, smoke-free lobbies/ fire lift lobbies, internal exit passageways, etc.
Effective Date: 1 Mar 2023
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Explanations & Illustrations
Clause 3.7.7a. : Use of fire shutter
Figure 3.7.7a.
The employment of fire shutter to substitute compartment wall is now permitted provided the fire shutter in-lieu of compartment wall meet stability, integrity and insulation provisions when tested to BS 476: Part 20-23. Do note that placement of combustible items around fire-rated shutter is not allowed.
Amendment History
| 3.7.7a. |
1 Mar 2023 |
1 Mar 2023 |
Revised/Clarifications |
Use of fire shutter
a. General
A fire shutter is permitted to be used as compartment wall, except for the fire compartmentation of Fire Command Centre (FCC) and means of escape, which include exit staircases, smoke-free lobbies/fire lift lobbies, internal exit passageways, etc.
b. ……….
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1 Mar 2023 |
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b. Fire resistance
The fire shutters, which are used to protect openings in compartment wall/floor, shall have the necessary fire resistance including thermal insulation, not less than that of the compartment wall/floor. However, fire shutters, which are installed at the edge of atria, voids such as escalator void areas and between floors, and door way, need not have thermal insulation.
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Explanations & Illustrations
Clause 3.7.7b. : Use of fire shutter
Figure 3.7.7b
The fire shutters, which are installed at the edge of atrium, void facing escalator and at door way are intended as relaxation. The reason for not requiring insulated fire shutter at door way is because the opening width is basically not overly big. The conventional fire door need not be tested to conform to insulation criterion. Hence, vertical fire shutter to substitute fire door will not be required to subject to insulation provision. All habitable spaces enclosed by the fire shutter are to be provided with exit for the occupants to escape either via a side door or a wicket door.
c. Operation
The commonly used shutters such as vertical, horizontal and lateral fire shutters shall comply with SS 489 and the following:
(1) Vertical fire shutter operated by gravity during a fire
Upon activation by a fire alarm system or fusible link, the operating mechanism of curtains/leaves of the vertical fire shutter shall be released. The curtain/leaves shall descend under gravity at a controlled rate.
(2) Electrically-operated vertical, lateral and horizontal fire shutter (fusible link is not required)
Upon activation by fire alarm system, the electrical motor shall drive the curtains/leaves to descend and shall be backed up by emergency power supply. The power and signal cables shall be fire-rated.
(3) Activation time and closing speed
(a) For vertical fire shutter with height not exceeding 6m, the maximum time for full closure of the fire shutter shall not exceed 30 secs from time of activation, with a descending speed not exceeding 0.2m/sec.
(b) For vertical fire shutter with height exceeding 6m and not more than 12m, the maximum time of full closure of the fire shutter shall not exceed 60 secs from time of activation, with a descending speed not exceeding 0.2m/sec.
d. Mode of activation
The mode of activation for fire shutters at different locations shall be as follows:
(1) Fire shutters as separating wall between two buildings (if allowed in accordance with Cl.3.6.2)
(a) Two buildings separated by a common fire shutter:
Both gravity-operated and electrically-operated fire shutters shall be linked to the fire alarm systems of both buildings and shall be activated by the fire alarm system of either building. Activation solely by fusible link is not permitted.
(b) Two buildings separated by two separate fire shutters:
Both gravity-operated and electrically-operated fire shutters shall be activated by the fire alarm system of its own building. Activation solely by fusible link is not permitted.
(2) Fire shutters as compartment wall/ floor for limiting compartment area and cubical extent
Fire shutters as compartment wall/ floor for limiting compartment areas and cubical extent, as compartment between different purpose groups, as compartment of special rooms such as kitchen, electrical room, store room, etc. and as compartment of basement passenger/ goods lift lobby: and as compartment of basement passenger/ goods lift lobby:
(a) For gravity-operated vertical fire shutters, activation by fusible link is acceptable.
(b) For electrically-operated fire shutters, activation shall be by local smoke detectors.
(3) Fire shutters as compartmentation at atrium/ voids or between floors (being part of the engineered smoke control design)
Only electrically-operated fire shutters are permitted. The signal to operate the respective fire shutter shall be from a dedicated smoke detector installed at the respective smoke zone.
3.7.8 Fire safety signage for fire shutter and smoke curtain
Effective Date: 15 Mar 2021
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Rationale - Clause 3.7.8
The additional exit directional signage on the fire shutters/smoke curtains is to guide occupants to the nearest exits as the lowered fire shutters/smoke curtains may block the building exit and/or directional signs during an fire emergency.
Amendment History
| 3.7.8 (dated 15 Sep 2020) |
15 Mar 2021 |
15 Mar 2021 |
Revised |
Exit directional signage on fire shutter and smoke curtain Exit directional signage marked with an arrow and the word “EXIT” shall be prominently painted /pasted on fire shutters/smoke curtains to redirect building occupants to the nearest exits if the activated shutters visually obscure the building exit and/or directional signs. The signage shall be reflective and the letters at least 100mm in height. |
15 Sep 2020 |
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a. Exit directional signage marked with an arrow and the word “EXIT” shall be prominently painted/ pasted on fire shutters/ smoke curtains to redirect building occupants to the nearest exits if the activated shutters visually obscure the building exit and/ or directional signs. The sign shall be reflective and the letters at least 100mm in height.
b. Signage for alerting persons not to impede the operation of fire shutters/ smoke curtains shall be permanently displayed at prominent locations and suitable intervals close to the descending paths of the fire shutters/ smoke curtains. The lettering of the sign shall be at least 25mm high in a colour contrasting with the background and states the following where applicable:
(1) “FIRE SHUTTER – KEEP CLEAR”
(2) “SMOKE CURTAIN – KEEP CLEAR”
3.7.9 Emergency generator room
a. An emergency generator room shall be compartmented as stipulated under Table 6.4A.
b. An emergency generator can be located in an external space provided:
(1) the setback distance between the outdoor emergency generator from other surrounding hazards except water tank shall be at least 3m; and
(2) if there is more than one outdoor emergency generator, each outdoor emergency generator shall be separated from the other by a dividing wall of masonry construction for the full length and height of the adjacent outdoor emergency generator.
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Rationale - Clause 3.7.9b
The requirements is to ensure that emergency generators located outdoors are adequately protected from by any nearby fire which may affect their operation during an fire emergency.