Requirements for escape stairs, passageways and doors This subject is dealt with in great detail in The Building Regulations 2000 Fire Safety Approved Document B 2006 edition Amended 2007 and contains finite and detailed calculations as required for escape stairs.
Overview.
Within the various building regulations, there are in principle two defined types of stairway, the accommodation stairways ( a stairway, which is provided for the convenience of occupants) and the type with which this element is more concerned, Escape stairs or Protected stairway, defined as a stairway which is adequately protected from fire in adjoining accommodation by fire-resisting construction and either discharges through a final exit or a protected route leading to a final exit.
Another aspect associated with escape stairs is the method of phased evacuation:
"Where it is appropriate to do so, it may be advantageous to design stairs in high buildings on the basis of phased evacuation.
In the phased evacuation, the first people to be evacuated are all those of reduced mobility and those on the stories most immediately affected by the fire, usually the floor of fire origin and the floor above. Subsequently, if there is a need to evacuate more people, it is done two floors at a time. It is a method which cannot be used in every type of building, and it depends on the provision (and maintenance) of certain supporting facilities such as fire alarms. It does enable narrower stairs to be incorporated than would be the case if a simultaneous evacuation were used, and has the practical advantage of reducing disruption in large buildings"
B1 GENERAL PROVISIONS extract from the main article
Construction of escape stairs.
6.19 The flights and landings of every escape stair should be constructed of materials of limited combustibility in the following situations:
a. if it is the only stair serving the building, or part of the building unless the building is of two or three stories and is in Purpose Group 1(a) or Purpose Group 3;
b. if it is within a basement story (this does not apply to a private stair in a maisonette);
c. if it serves any story having a floor level more than 18m above ground or access level;
d. if it is external, except in the case of a stair that connects the ground floor or paving level with a floor or flat roof not more than 6m above or below ground level.
e. if it is a fire fighting stair
7.14 Passageways and doors Passageways or corridors and doors form part of the escape route(s) in a building and have similarities with details in previous sections in that there are two classifications, protected and unprotected.
Protected Escape Routes are corridors leading to the open air, that is entered by fire doors.
Unprotected Escape Routes are normally corridors linking parts of a building, sometimes connecting to protected escape routes.
This is also a dead-end corridor meaning that entry and escape can only be by one route
The situation depicted by this diagram shows an unprotected corridor joining the main corridor, itself an unprotected route.
Looking at the diagram, we can see that fire-resistant doors and fire-resistant walls are marked in red and that the fire doors have self-closing mechanisms (SC).
Fire doors are provided in buildings to protect escape routes from the effects of fire so that occupants can safely reach the Final Exit, and also to protect the contents and/or the structure of the building by limiting the spread of fire.
Fire doors provided to protect the Means of Escape should:
a. be capable of achieving a minimum Fire Resistance (FR) for the integrity of 30 minutes;
b. smoke at ambient temperature – by use of smoke brushes etc.
c. give limited smoke at medium temperatures – by intumescent seals etc.
7.15 Protection of escape routes Protection in this sense is provided by the materials and construction of doors, walls, divisions and ceilings etc along the fire route and the ability of such to resist combustion. The term applied is Fire Resistance and the minimum time requirement to qualify as fire resistant is as quoted “Generally, a 30-minute standard is sufficient for the protection of means of escape”.
Any internal glazing within the escape route must be kept to a minimum. In cases where this is unavoidable, the glazing will need to be of 30 minutes' fire protection.
In an earlier section of this element, we covered compartmentation. The same methods of stopping fire spread and combustion are applied in the protection of escape routes; the escape routes in this aspect are in fact compartments.
7.16 Emergency lighting and signs One of the fundamental requirements of fire safety and fire safety legislation is to ensure that persons within the building can evacuate safely in the event of an emergency.
Overriding all these factors is the usability of the escape route when required. This relies on occupants of the building being able to find the escape route and, as far as possible, safely traverse the route to a place of safety.
It is inappropriate to depend on natural lighting as not all emergencies occur during daylight hours; also, many buildings are not properly lit internally by daylight.
Mains lighting power can be lost during a fire and the cable serving the lighting circuits may be destroyed. The electrical system may also be ‘isolated’ or turned off to remove the
threat of electrocution.
For this reason, a lighting system should be available in an emergency such as in the event of a fire.
The requirement for emergency lighting, its type, and location, is defined through the carrying out of a risk assessment.
Definitive information and specifications for emergency lighting systems are subject to British Standards, which are:-
BS EN 50172:2004 Partially replaces BS 5266-1:1999.
BS EN 50172:2004 specifies requirements whereas BS 5266-1 is a code of practice giving recommendations.
Overview.
Within the various building regulations, there are in principle two defined types of stairway, the accommodation stairways ( a stairway, which is provided for the convenience of occupants) and the type with which this element is more concerned, Escape stairs or Protected stairway, defined as a stairway which is adequately protected from fire in adjoining accommodation by fire-resisting construction and either discharges through a final exit or a protected route leading to a final exit.
Another aspect associated with escape stairs is the method of phased evacuation:
"Where it is appropriate to do so, it may be advantageous to design stairs in high buildings on the basis of phased evacuation.
In the phased evacuation, the first people to be evacuated are all those of reduced mobility and those on the stories most immediately affected by the fire, usually the floor of fire origin and the floor above. Subsequently, if there is a need to evacuate more people, it is done two floors at a time. It is a method which cannot be used in every type of building, and it depends on the provision (and maintenance) of certain supporting facilities such as fire alarms. It does enable narrower stairs to be incorporated than would be the case if a simultaneous evacuation were used, and has the practical advantage of reducing disruption in large buildings"
B1 GENERAL PROVISIONS extract from the main article
Construction of escape stairs.
6.19 The flights and landings of every escape stair should be constructed of materials of limited combustibility in the following situations:
a. if it is the only stair serving the building, or part of the building unless the building is of two or three stories and is in Purpose Group 1(a) or Purpose Group 3;
b. if it is within a basement story (this does not apply to a private stair in a maisonette);
c. if it serves any story having a floor level more than 18m above ground or access level;
d. if it is external, except in the case of a stair that connects the ground floor or paving level with a floor or flat roof not more than 6m above or below ground level.
e. if it is a fire fighting stair
7.14 Passageways and doors Passageways or corridors and doors form part of the escape route(s) in a building and have similarities with details in previous sections in that there are two classifications, protected and unprotected.
Protected Escape Routes are corridors leading to the open air, that is entered by fire doors.
Unprotected Escape Routes are normally corridors linking parts of a building, sometimes connecting to protected escape routes.
This is also a dead-end corridor meaning that entry and escape can only be by one route
The situation depicted by this diagram shows an unprotected corridor joining the main corridor, itself an unprotected route.
Looking at the diagram, we can see that fire-resistant doors and fire-resistant walls are marked in red and that the fire doors have self-closing mechanisms (SC).
Fire doors are provided in buildings to protect escape routes from the effects of fire so that occupants can safely reach the Final Exit, and also to protect the contents and/or the structure of the building by limiting the spread of fire.
Fire doors provided to protect the Means of Escape should:
a. be capable of achieving a minimum Fire Resistance (FR) for the integrity of 30 minutes;
b. smoke at ambient temperature – by use of smoke brushes etc.
c. give limited smoke at medium temperatures – by intumescent seals etc.
7.15 Protection of escape routes Protection in this sense is provided by the materials and construction of doors, walls, divisions and ceilings etc along the fire route and the ability of such to resist combustion. The term applied is Fire Resistance and the minimum time requirement to qualify as fire resistant is as quoted “Generally, a 30-minute standard is sufficient for the protection of means of escape”.
Any internal glazing within the escape route must be kept to a minimum. In cases where this is unavoidable, the glazing will need to be of 30 minutes' fire protection.
In an earlier section of this element, we covered compartmentation. The same methods of stopping fire spread and combustion are applied in the protection of escape routes; the escape routes in this aspect are in fact compartments.
7.16 Emergency lighting and signs One of the fundamental requirements of fire safety and fire safety legislation is to ensure that persons within the building can evacuate safely in the event of an emergency.
Overriding all these factors is the usability of the escape route when required. This relies on occupants of the building being able to find the escape route and, as far as possible, safely traverse the route to a place of safety.
It is inappropriate to depend on natural lighting as not all emergencies occur during daylight hours; also, many buildings are not properly lit internally by daylight.
Mains lighting power can be lost during a fire and the cable serving the lighting circuits may be destroyed. The electrical system may also be ‘isolated’ or turned off to remove the
threat of electrocution.
For this reason, a lighting system should be available in an emergency such as in the event of a fire.
The requirement for emergency lighting, its type, and location, is defined through the carrying out of a risk assessment.
Definitive information and specifications for emergency lighting systems are subject to British Standards, which are:-
BS EN 50172:2004 Partially replaces BS 5266-1:1999.
BS EN 50172:2004 specifies requirements whereas BS 5266-1 is a code of practice giving recommendations.
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