Fire testing, product performance and classification for fire rated windows

We receive hundreds of inquiries each year asking us to quote for fire rated windows, some of which carry a basic requirement for a 30 or 60 minute window, others with complex specifications referencing a raft of standards, some of which are appropriate, others of which are less so!

This is a complex subject, but here we seek to highlight some of the standards referenced to understand how they work together to build a basic picture evidencing the performance of a fire rated glazing product.

Test methodology:

BS EN 1363-1 Fire resistance tests. General requirement – this stipulates many of the test parameters and is referenced in conjunction with specific product performance standards.

Product specific performance standards:

For our windows (non openable) and fixed screens, the performance is tested to BS EN 1364-1 Fire resistance tests for non-loadbearing elements. Walls.

Curtain Walling is tested to BS EN 1364-3 Fire resistance tests for non-loadbearing elements. Curtain walling – full configuration (complete assembly) and BS EN 1364-4 Fire resistance tests for non-loadbearing elements. Curtain walling – full configuration (part configuration) which additionally examines the fire resistance to internal and external fire exposure for the combination of the spandrel panel, the perimeter seal and/or the fixing of the framing system.

Doors and fire rated openable windows are tested to BS EN 1634-1 Fire resistance and smoke control tests for door and shutter assemblies, openable windows and elements of building hardware. For doors that additionally offer smoke control these are tested to BS EN 1634-3 Fire resistance and smoke control tests for door and shutter assemblies, openable windows and elements of building hardware. This identifies the performance of products intended for the purpose of controlling the passage of (cold and warm) smoke in case of fire.

The results of the test will then be written into a report, which will form the basis of the classification of the product.

We often see references to BS 476-22 Fire tests on building materials and structures. Methods for determination of the fire resistance of non-loadbearing elements of construction. It should be noted that this standard was drawn up over 35 years ago and there is no third-party certification to support it. Consequently, it is not possible to get a classification for products tested to this standard.

Please note that this list is not exhaustive as certain performance requirements may be considered based on EXAPs due to the potential enormity of variants to be tested. These define the criteria, under which, experts can extend the field of application for a product.

Front and back of EI60 silicone jointed glazed screen following a successful test

Images courtesy Pyroguard (UK) Ltd

Classification of products:

The classification for these products is under BS EN 13501-2 Fire classification of construction products and building elements. Classification using data from fire resistance tests, excluding ventilation services.

The classification is then referenced as follows:

R – Load bearing capacity - this is not applicable to fire rated glazing (except for rooflights)

E – Integrity - resisting the spread of flames, smoke and toxic gases from one side to the other

I – Insulation - measuring the transfer of heat from the fire side to the non-fire side, on the face of the fire separating element

W – Radiation - measuring the transmission of radiant heat at a distance from the face of the fire separating element (whilst extensively referenced in Europe, this is not commonly used in the UK. If insulation requirements are met, it is assumed that radiation requirements are also satisfied).

Performance is then given in time (generally in 30 minute intervals) based on the time surpassed during the fire test, so the classification would be based on the successful parameters and the time achieved e.g. EI30.