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Transparent design, however, requires special attention regarding fire resistance.  Standard glass types do not have significant resistance against fire. In particular, products used in impact safety and security applications have problems in the event of fire: for example, toughened glass is susceptible to sudden unpredictable and catastrophic failure, and the plastic interlayer in standard safety and security laminates is liable to melt and burn.  Fire-resistant glass has therefore been developed to look and function in other respects just as any other glass product.  But there are a number of different types of fire-resistant glass which differ significantly from one to another, although they may be superficially similar in basic classification.  Scope of application, level of performance in fires, glazing sizes, reliability and framing options all differ from one fire-resistant glass to another. 

So, to ensure appropriate design, what guidance is appropriate? What questions should be asked?  Above all, where fire-resistant glazing is concerned, generalisations and assumptions are unsafe.

The best advice, always, is to seek specific help from a specialist in fire-resistant glazing, such as the responsible manufacturer or an accredited installer.

There are important rules to observe.  The following list might serve as a prompt and aide memoir:

Fire-resistant glass should only be installed as part of an approved fire-resistant glazed system of matched components (which includes the frame, beads, seals and fixings).  

•Supporting test evidence is essential, provided by a test report. 

•If assessments are used then these must be based on relevant test evidence;

•The fire-resistant glazed system must be installed as tested; last minute changes or short cuts are not acceptable.  All the components – not only the fire-resistant glass – should be named and identified unambiguously. 

Fire-resistant glazed systems can be found in a variety of situations as part of a fire protection strategy to provide protected escape, fire separation and building compartmentation.  Common applications are as panes or fully glazed assemblies in screens and partitions, in overhead glazing, and as variously sized vision panels in fire doors and walls. External fire-resistant glazing is also necessary in windows and door panels to protect users of outside stairs and transit routes, and to limit the risk of fire transfer to adjacent buildings.  Fire-resistant glazed approvals are even now available for far more demanding applications such as integral load-bearing fire-resistant glass floors. And because of the risk of fire movement by the mechanism of break out and break in through windows, increasing consideration needs to be given to the application of fire-resistant glass in facades to prevent fire transfer in the same building either from floor to floor or on the same level across internal corners.  This is increasingly important because of the fashion for ever taller and more complex high value and high impact commercial buildings. 

The growth in risk-based approaches to fire safety design means more reliance on the predictable performance of materials and structures.  In turn this requires close attention to material performance and product specification.  Glass has a venerable history of use over centuries, a familiarity which may so easily lead to assumptions and misconceptions.  Fire-resistant glazing needs to be recognised as a high performance technology in its own right, designed to counter a particular modern risk in today’s cities.  And, just like any modern high-tech product, the best can only be obtained from the technology if the requirements are recognised and given attention in the detail of its application. This applies equally to fire-resistant glazing as it does to any other modern fire protection system.