Fire, generally doors

Fire resistance Doors should display evidence of conformity to BS 476, normally by the inclusion of a colour coded plug in compliance to BS 8214. In general all fire doors and their assemblies must be capable of resisting fire for 30 minutes. The notable exception to this is for fire doors that have been provided to break up a long (over 12 metres) corridor, and doors protecting dead ends, in which cases only 20 minutes fire resistance is required. Any glass fitted in the door should be similarly fire resistant and should be securely fitted with fire resistant beading. 

Tig. 107 shows the arrangement and position of the retorts, of which there are generally five placed pyramidally in one furnace. Rig 108 is a front view of the same. To the three fires of the furnace, A is the door, C the grate, and n the ash-pit, with a well, D—Tig. 107,... 

Commercial fire-retardant treatments generally do not add significantly to the fire endurance of assemblies. It is often more advantageous from the cost standpoint, either to use thicker wood members or to select species with lower charring rates, than to add the cost of the fire-retardant treatment. In some assemblies, however, it has been found worthwhile to use some fire-retardant-treated components in order to gain the extra time which will bring the fire endurance time up to the goal desired. For example, treated wood studs in walls and treated rails, stiles, and cross bands in solid wood doors have been used. 

Colored Fires for Theaters.—We give below a table of the composition of the mixtures commonly employed for colored Dree in tableaux, etc. These fires, however, should never be used within doors, as the gaseous products of some of them are extremely poisonous. The lime light lanterns and lenses of suitably colored glass have now been generally substituted tor these Ares, and give much better results. 

Generally, no container should be stored within 2 m of any window, escape route or door. Much will depend on the nature of the substances stored and the design of the storage area. Where a storage area is constructed with fire resistant walls, these distances can be reduced. 

Side firing in-and-ouf furnaces is more difficult because generally one long wall is a door or row of doors, which makes it difficult to measure temperature, increases heat losses, and prevents use of burners on the door wall. However, if the temperature uniformity requirements for the product are not stringent, the burners can be located in the back wall firing foward the doors with control thermocouples inserted through the roof. 

The portion of an exit route that is generally separated from other areas to provide a protected way of travel to the exit discharge from the effects of an incident. An example of an exit is a 2-hour fire-resistance-rated enclosed stairway that leads from the fifth floor of an office building to the outside of the building. Exits include exterior exit doors, exit passageways, horizontal exits, and separated exit stairs or ramps. See also Fire Escape. 

The two key features in planning a means of escape are, firstly, the travel distance which is the distance a person must travel from any point within a floor area to the nearest exit to a protected stairway, escape route or to a place of safety. In general 18 m is considered to be the maximum travel distance if there is only one exit and 45 m if there is more than one. Secondly, except in special circumstances, at least two escape routes in substantially opposite directions should be provided for every storey or level of a building. The width of the exit and the escape route is governed by the number of people who may be present on the storey or level but the minimum permitted width is 826 mm. Where a corridor forms part of the travel distance it should be enclosed to restrict the spread of smoke. If the corridor is a dead end then it must have at least half-hour fire resistance walls and ceilings so that people can safely pass by a room if it is on fire. If the corridor connects alternative exits it should be fitted with smoke stop doors mid-way between the exits. 

As indicated above, the spread of fire and smoke can be controlled by both passive and active means. On the one hand, the measures include separation of buildings com-partmentation fire walls fire doors fire and smoke shutters controls on air conditioning and pressurization of critical areas such as stairways and, on the other, detectors and alarms extinguishers hose reels and sprinkler systems. Smoke detectors generally detect fire more quickly than heat detectors. 

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