Fire-resistant glazing: are regulations up to date?
Fire costs the UK economy an estimated £3.5 billion per year. With glass becoming an ever more dominant material in the built environment, manufacturer Pilkington, has released a new report – The Burning Issue – to ask if the glazing industry and its clients are doing enough to make buildings safe by design.
One trend that has defined the aesthetics of today’s built environment is the emergence of glass as one of the most commonly used building materials.
In everything from commercial office space and shops to residential and even functional industrial buildings, glass is increasingly being deployed to partition spaces where previously concrete, bricks and mortar or plasterboard might have been used.
This places great importance on the ability of glass to stand up to and prevent the spread of fire through different areas of a building. If we are to preserve the safety of our buildings and those who use them, it’s essential that glazing design and installation keeps pace with the growing demand for glass as a functional construction component.
Technology has progressed rapidly in recent years in terms of the ability of glazing to stand up to fire for extended periods of time. At the same time, the use of larger pane sizes has been tested and approved for use in sensitive settings, and those panes can deliver high levels of clarity, while maintaining the required safety levels.
But while these developments have provided architects and interior designers with many more options for creating bright, airy spaces, they have also created challenges. How does the industry ensure the consistent quality of fire-resistant glazing across the market? How do we guarantee that the appropriate products are always used in the right settings? Are current building regulations fit for purpose when applied to the latest fire-resistant glazing technology?
These are the questions we address in our new report, which includes contributions from the Glass and Glazing Federation and specialist installer, Wrightstyle.
Regulation – is it time for an overhaul?
In his contribution to the report, Steve Rice, director of technical affairs at the Glass and Glazing Federation focuses on the suitability of the regulations contained in Approved Document B (AD B). He comments:
The primary focus of AD B is to save lives and, in that aim, it has clearly been a success. In 1981 there were 967 deaths resulting from building fires, compared with 256 in 2015. This is a steady decline of 20 deaths per year.
However, the record is less encouraging when we look at fire-related property and business losses. While the number of fires has fallen, average loss per fire has risen significantly and, as a result, the evidence suggests that there has been little reduction in the overall cost to the economy.
There is recognition in the industry that AD B needs to be improved to bring it more in step with current practice in building design, construction and product supply.
However, it’s vital that what emerges stays true to the core principles of fire separation and compartmentation.
The focus can now no longer be solely on preventing fatalities, but must be on the wider risks fire presents in modern buildings, both to property and people, and this is particularly relevant to the application of glass.
Currently, the emphasis of AD B is on getting people out of a building before conditions become unsafe and structural stability is threatened. AD B considers integrity performance – that is, ensuring the glass continued to present a physical barrier – to be sufficient. As a result, emphasis on thermal insulation – the ability of the glass to prevent the transfer of radiant heat from one space to another – has been minimal.
Better property protection and higher levels of assured safety for individuals in more complex modern buildings needs to go beyond this. It will require a greater use of insulation and longer protection times.
Fire-resistant glass products have been developed to suit a wide range of applications, delivering higher levels of integrity and insulation, and have achieved proven performance based on extensive testing. The guidance should better recognise these advances.
Keeping pace with technology
The developments in technology have been significant across the board and there is now more product choice and greater levels of performance to exploit.
This is particularly illustrated by high-performing clear, laminated integrity glass products, that can also provide a good level of insulation. For example, it is now possible to specify these products with 30 minutes’ integrity and 15 minutes’ thermal insulation.
Regulations need to keep in touch with what they regulate. And, despite its success, AD B is somewhat lagging behind. A makeover is required but, in the name of fire safety, the regulations must maintain what is good and build on it to better reflect modern practices and technologies.
Addressing the full costs of fire
Also contributing to the report, Tim Kempster, managing director of Wrightstyle, echoed Steve Rice’s view that the current way of assessing the risks presented by fire is often not fit for purpose. Tim Kempster writes:
Protecting a building and its occupants against fire starts on the drawing board, so hazards are considered and mitigated from the word go.
In Tim’s view, compliance with fire regulations is not sufficient. They deal only with protecting human safety and, while this is clearly by far the most important concern, it is by no means the only one.
All fires are disruptive and often they can shut down businesses, sometimes temporarily and sometimes permanently. With this in mind, it’s essential that the risk assessment takes into account more than just regulatory compliance.
Designers and specifiers of fire-rated glass need to ask questions like: ‘if fire does happen, can we quickly move manufacturing elsewhere?’ and ‘if we lose data on-site, is all that business-critical information also held elsewhere?’. If these things aren’t possible, the potential impacts must be taken into account when specifying the glass.
Modern glazing systems can play a central role in the resulting mitigation strategy by providing complete protection against radiant heat– the means by which fire spreads through a building. It can be used as curtain walling, internal doors, floors or fire screens – creating a barrier for up to three hours, giving more than enough time for a safe evacuation and for emergency services to contain the blaze effectively, minimising losses.
Of course, before any glazing system can be used in this way, it is critical that it is tested and certified to local or national standards to demonstrate its suitability.
This applies not only to the glass, but also to the specific framing system being used and the way the two work as a system in the specific arrangement intended.
That means insisting on comprehensive fire test certification that covers both glass and frames because, in a fire, if one fails, both fail, with potentially catastrophic consequences.
In speaking to leading experts in the field of fire-resistant glazing, it’s clear there are some concerns both over the current standards designers and specifiers are legally required to meet, and over the approach to risk assessment taken by some building owners, their advisors and fire engineers.
The industry has achieved great success in reducing the number of deaths caused by fires in buildings, and now the focus needs to be on protecting the economy against the financial losses that it continues to cause.
For more information, go to www.pilkington.co.uk/fire