Means of Escape Flashcards
What is the function of means of escape?
To allow occupants to escape from a building during a fire without being overcome by heat or smoke
The escape time must be shorter than the time taken for heat and smoke to spread.
Define means of escape.
A continuous and unobstructed fire resisting passage in a building for occupants to reach a place of safety during an emergency
A place of safety is typically an unenclosed space at ground level, far enough from the building.
What must be ensured regarding means of escape?
They must be immediately available for use at all times
Exits should be readily accessible, doors must always be openable, and unobstructed during occupancy.
Do all buildings require means of escape?
Yes, means of escape must be provided for all buildings
The provision varies based on factors such as the nature and size of the building, its use, and the behavior of occupants.
What is one example of how means of escape provisions differ?
A hotel will need more stringent means of escape compared to an office building
This is due to the different occupancy types and potential risks involved.
What are the three stages of escape in buildings under Purpose Groups III to VIII?
- Portion within Functional Space to Exit Staircase
- Exit staircase
- Exit discharge
Each stage addresses different aspects of safe evacuation.
What is critical in Stage 1 of the escape process?
Occupants must be able to get out within a prescribed distance to the nearest exit staircase door
This distance is specified in Table 2.2A.
What protection do occupants have in Stage 2?
They are protected from exposure to fire risk throughout their descent down the staircase
This stage ensures safety until they reach the final exit at ground level.
What must occupants be able to do in Stage 3?
Discharge into the open external space at ground level
At this point, they should no longer be in danger from fire or smoke.
What is the general requirement for exits in a building?
Every floor must have two exits
This is to ensure safety and accessibility in emergencies.
What principle applies to the positioning of exits?
The ‘remoteness of exits’ principle
This principle ensures exits are as far apart as possible to maintain safety.
When can two exits be considered ‘independent’?
When they comply with the ‘remoteness of exits’ principle
This requires a separation distance greater than half the diagonal dimension of the room.
What is the separation distance requirement for exits?
More than half of the diagonal dimension of the room
This ensures that if one exit is blocked, the other remains accessible.
What must be considered when determining exit requirements?
Flow of people through the exits and travel distances
This includes the occupant load and exit capacity.
How is occupant load determined?
From the room area and the occupant load factor
This calculation ensures the safety and capacity of exits.
What determines the exit capacity of a staircase?
Its physical width and number of persons per exit width
This is outlined in Table 2.2A.
What is the role of exit staircases?
They serve simultaneously all levels above ground level
This ensures that the staircase is adequately sized for the highest occupant load.
What is the generally accepted rate of occupant flow through exits?
40 persons per unit width per minute
This figure is based on past experiences, particularly during fires.
What is one unit width equivalent to in the Fire Code?
0.5 m or 500 mm
This measurement corresponds to the shoulder width of an average person.
If the capacity of an exit door is 80 persons per unit width, what does this mean?
80 persons can pass through a unit exit width in one minute
This is based on a unit width of 500 mm.
True or False: Time is explicitly specified in the Fire Code regarding the flow of persons through exits.
False
The Fire Code does not specify time for the flow of persons.
Occupant Load/Number of persons allowed in room =
[area of space ( m2)]/
[occupant load factor (m2
/person)]
Direct Distance (DD)
Shortest distance from most remote point within the room to nearest room exit, ignoring partitions & fittings such as furniture.
What is travel distance?
The actual distance required to be travelled from the most remote point in a room to the room exit.
What should the direct distance be in relation to travel distance?
About 2/3 times travel distance.
What is maximum travel distance?
The maximum distance required to be travelled from the most remote point in a room to the room exit when the room is fully occupied.
What does ‘two-way travel’ refer to?
A situation where occupants within a space have the choice of more than one route from a splitting point (A) to reach multiple exits.
What is a one-way travel distance?
A distance (AB) where occupants can only travel in one direction to reach the exit.
What is critical for occupants at the most remote point of a level during a fire?
To escape from a fire before being overcome by heat and smoke.
Why is it difficult to calculate precise escape times during a fire?
Because people, buildings, and fires vary.
How do Fire Codes specify regarding travel distances?
Distances based on past fire experiences.
What should exits and access facilities be like?
Clearly visible or indicated, readily accessible, and unobstructed.
What is required for every occupant or tenant regarding exits?
Direct access to required exit(s) without passing through other occupied spaces.
What is essential for tenants on a level occupied by more than one tenant?
Direct accessibility to alternate exit staircases without entering other tenancies.
How can direct accessibility to exits be facilitated for tenants?
Via common corridors or lobbies accessible to all tenants on that level.
What is the minimum clear width of an exit door opening?
Not less than 850mm.
Free card
slay queen
Fill in the blank: The minimum clear width of an exit door opening should not be less than _______.
850mm.
Exit and access doors
- Exit doors: Manually openable, no key/tool needed.
- Fire-rated and must open in exit direction.
- Halls & auditoriums: Doors stay unlocked, use panic bolts.
- Staircase doors: Must not block egress.
- Fire doors: Have vision panels, self-closing devices.
- No revolving doors for exits.
Fastenings on doors
- Generally cannot be locked.
- Exceptions: Allowed for security but must open in emergencies.
- Unlocking methods: Panic bolt, thumb-turn, or fire alarm-linked release.
Provision of Electronic Locking Devices
- Allowed if linked to fire alarm & sprinkler system for emergency release.
- Smart card, magnetic bar, and electro-mechanical locks must follow safety regulations.
- Fire alarm/sprinkler activation must automatically unlock doors until reset.
- Manual green release device required for emergency override.
- Fail-safe mechanism: Unlocks on power loss or system fault
What words should be displayed above the push-bar on doors fitted with panic bolt or panic latch?
Push bar to open
What notice should be displayed on fire doors?
Fire door – Keep shut
What should fire doors that close automatically on operation of fire detectors display?
Automatic fire door – Keep Clear
What is the purpose of exit lighting facilities?
To show occupants the location of exits and lead them out of the building
Which buildings must have artificial lighting facilities for exits?
All buildings except Purpose Group I
Emergency lighting must be provided in all corridors and lobbies of which buildings?
All buildings except Purpose Group I
What is the maximum delay allowed between the failure of normal lighting and the energisation of exit lighting?
1 second
What is the purpose of emergency lighting in the event of a fire?
To illuminate escape routes on failure of the mains electrical supply
For which occupied areas must emergency lighting be provided?
Along paths leading to corridors, lobbies and exits where the distance exceeds 13 m or over the whole area if no explicit paths
In which locations must emergency lighting also be provided?
- Lift cars
- Fire command centres
- Generator rooms
- Basement car parks
- Fire pump rooms
- Areas of refuge within same building
What is the maximum delay for emergency illumination during switchover from normal supply to secondary source?
15 seconds
What must be clearly indicated at every exit on every floor in buildings except Purpose Group I and II?
An exit sign placed over the exit door
What should be provided if the location of exits is not visible in long corridors or open floor areas?
Directional signs
What type of signs must be provided in hotel accommodation floors including boarding houses?
Low level or floor mounted exit and exit directional signs
What should be placed at strategic locations inside staircases serving upper storeys and basements?
Appropriate signs, including pictorials, to direct occupants out of the building
What is the requirement for self-illuminating exit and directional signs?
Engraved with letters in green and powered by radioactive material
What is the luminance requirement for self-illuminating fire safety signs?
2 to 25 candela per square metre
What is the purpose of low-level or floor-mounted signs?
To aid building occupants to get to the exit in a smoke-filled environment
