OAG Fire - Glossary

Fire Doors – Doorset designed to maintain fire separation between compartments for a specified time period. The fire resistance period will be determined by fire resistance according to either BS 476-22 or BS EN 1634-1.

Doors tested to BS 476-22 will have a typical resulting classification of FD30, FD60, etc. For fire resistance in terms of integrity only.

Doors tested to BS EN 1634-1 and classified according to BS EN 13501-2 will have a classification of E30, E60 and so on for doors providing fire resistance in terms of integrity only, or EI30, EI60 and so on for fire resistance in terms of integrity and insulation. 

Smoke Doors – Doorset, usually fire resistant, designed to resist the passage of smoke at ambient temperature. Testing will be to either BS 476-31.1 or BS EN 1634-3. Both tests are similar and measure the linear leakage rate of the seals on the top and vertical edges of the door, the bottom edge is taped up. 

Doors tested to BS 476-31.1, assuming they are fire doors, will be classified with the additional suffix ‘S’ as FD30S, FD60S, etc.

Doors tested to BS EN 1634-3 and classified according to BS EN 13501-2 will have the additional suffix ‘S’, for example, E30S or EI60S. 

To satisfy the maximum leakage value set out in the building regulations guidance, the door must either incorporate an effective threshold seal (proven by test) or have a threshold clearance not exceeding 3mm. 

Assessment – Field of Application Report prepared by an Approved Body or testing facility according to Passive Fire Protection Forum (PFPF) guidelines to define the limitations of a particular product or system, based on fire test evidence. Assessments are typically written according to the Extended Application (EXAP) principles of EN 15725:2010 and can either be for the standard product range or specific to a project application. 

Compartmentation – Enclosing a space, which may be subdivided and separating it from the adjoining spaces within the building by elements of construction having a specified fire resistance. 

Fire Resistance – Ability of a component or construction of a building to meet, for a stated period of time, some or all of the appropriate criteria specified in the appropriate part of BS 476 or BS EN 13501-2. The fire resistance classification periods, in terms of integrity and insulation are a measure of their performance in a fire test, not the actual time for which the element will function in a real fire. 

Integrity – Ability of a separating element when exposed to fire on one side, to prevent the passage of flames and hot gases or the occurrence of flames on the unexposed side, for a stated period of time in a standard fire resistance test (i.e. the relevant part of BS 476 or BS EN 13501-2). 

This may be expressed as integrity criterion ‘E’. 

Insulation – Ability of an element of construction to withstand fire exposure on one side only, without the transmission of fire as a result of significant transfer of heat to the unexposed side, as measured in standard fire resistance test methods that measure surface temperature on the unexposed side of the element (as defined by BS EN 13501-2). 

This may be expressed as insulation criterion ‘I’. 

Fire Test – Fire resistance can be determined through destructive fire testing designed to replicate the product’s intended end-use. The specimen to be tested is built into an appropriate supporting construction which is then built into a restraint frame and mounted on the front of a furnace. The temperature within the furnace is controlled according to an internationally accepted time/temperature regime. 

Tests to BS 476 are normally representative only of the construction under test and cannot be varied, other than by assessment. 

Tests to standards prescribed by BS EN 13501-2 include a field of direct application (DIAP). This specifies a limited range of changes that can be made to the tested product when in use. Other changes would need to be determined by reference to the extended application (EXAP) standards in cooperation with the fire testing authority. 

DIAP – The field of direct application within the fire test standards specify permitted changes that can be made to the tested sample when in use, assuming a specified overrun is achieved in the fire test. This may include proportional increases in size or in the thickness of sample materials. 

EXAP – Procedure for extending or varying the application of a pre-determined range of fire test results using defined rules. This is carried out by the fire testing authority, not by the manufacturer themselves. 

EXAP Standards include:

  • BS EN 15254-4 – (fire resistance of non-loadbearing walls – glazed constructions)
  • BS EN 15269-5 – (fire resistance of metal framed glazed door sets)
  • BS EN 15725 – (fire performance of construction products)

BS EN 13501-2 – This European standard defines the classification process for fire resistance, whereby the fire performance parameters obtained from the results of one test, or set of tests, or from a process of extended application are classified according to their performance characteristic. Specified test standards include:

  • BS EN 1363-1 – (general requirements for fire resistance tests)
  • BS EN 1364-1– (fire resistance of walls, including non-loadbearing partitions)
  • BS EN 1364-3 – (fire resistance of curtain wall  systems)
  • BS EN 1634-1 – (fire resistance of doors)
  • BS EN 1634-3 – (smoke control of doors)

Supporting Construction – A form of construction used to close off the furnace and to support the non-loadbearing sample being evaluated in a fire resistance test. BS EN 1363-1 specifies forms of standard supporting construction for use in fire resistance tests which have a known resistance to thermal distortion. 

Supporting constructions used in practice should not vary from that used in the fire resistance test unless permitted by the DIAP or considered in EXAP.

BS 476-22 – The UK national standard for determining the fire resistance of non-loadbearing elements of construction (including doors and partitions) using the general principles described in BS 476-20.

Fire tests conducted according to BS 476-20 and 22 require the test construction to be “mounted as realistically as possible using the fixing details employed in practice“, so do not permit variation from the type of supporting construction used in fire resistance test. 

FIRAS – Third party installation inspection body, who access the procedures and competence of fire rated installers.

Certifire – This scheme, administered by Warrington Fire, allows a glass producer to have their glass assessed, following and exhaustive testing programme, into applications where a different glass product was tested or assessed.