ESCAPE ROUTES:• There must be at least one escape route from a. the main entrance door of every flat or maisonette b. the door of every communal room c. from every plant room.• An escape route must lead to a place of safety a. directly b. by way of a protected zone c. by way of an access deck or access balcony
In case of under ground fire • Egress windows… • Windows Below Ground Level: a)Sill height of window above floor: Not to exceed 44” b)Minimum opening area: 5.7 sq. ft. c)Minimum opening height 24” d)Minimum opening width: 20”
• Escaping with elevators.• Escaping through staircases.• Rescuing people by firemen and rescue services.• Rescuing with a telescopic ladder.• Rescuing people through the windows.• Emergency escaping with the rescue hose
four distinct Stages:• Stage 1 – escape from the room or area of fire origin.• Stage 2 – escape from the compartment of origin via the circulation route to a protected stairway or an adjoining compartment offering refuge.• Stage 3 – escape from the floor of origin to the ground level.• Stage 4 – escape at ground level away from .•
Means of escape from fire… • Time of evacuation • Travel distances • Number of Occupants • Calculation of Exit Widths • Calculation of Minimum Number of Exits
Time of evacuation:• Class ‘A’ construction – 3 minutes• Class ‘B’ construction – 2.5 minutes• Class ‘C’ construction – 2 minutes
Number of Occupants• Number of Occupants• Density Factor• Persons who may use the building• Calculating the Number of Occupants
Travel Distance:Places of Relative Safety• A storey exit into a protected stairway or to the lobby of a lobby approach stairway;• A door in a compartment wall or separating wall leading to an alternative exit;• A door which leads directly to a protected stair or a final exit via a protected corridor.
Calculation of Exit Widths • U = N / (40 x T) Where: - U = number of units required; N = number of occupants; 40 = standard rate of flow – constant; T = Flow time (i.e. 3 mins for Class ‘A’, 2.5 mins for Class ‘B’ and 2 mins for Class ‘C’)
Calculation of Minimum Number of Exits• E=U/4+1E = number of exits U = number of units of exit width (from exit width formula); 4 = size of largest exit permitted. 1 added to ensure there would always be at least one unit.
Methods & Designs practiced for escaping fire…
functioninga) A Supply Air System designed to blow into the protected spaces a sufficient quantity of air to maintain the required pressure level or air velocity. This will always be fan powered.b) An Exhaust Air System to enable the pressurising air to escape from the unpressurised areas of the building via the fire floor.This can be either a natural or fan powered method.
Fire escaping stairs A fire escaping stair is a special kind of emergency exit, usually mounted to the outside of a building or occasionally inside but separate from the main areas of the building.