With Dubai’s New Year celebrations overshadowed by another skyscraper fire, the focus has inevitably turned to the role of the external cladding in spreading the fire so quickly across the building.
But the problem can go much deeper than just external cladding panels – any building material that has not been adequately fire tested and rated has the potential to contribute to the spread of fire in a building.
Civil Defence has done much to make our new buildings safer and, under the leadership of the Civil Defence General Directorate in Abu Dhabi, many of the regulations have been standardised across all of the Emirates. Since Civil Defence is primarily concerned with safety of human life, however, much of the emphasis has been placed on active fire protection measures, such as sprinkler systems and fire hoses. Structure-based (passive) measures are largely focused on compartmenting the building to prevent fire spread and protect escape routes, with separating walls required to provide a minimum period of fire resistance, depending on location and building type/use.
Deciding exactly what level of fire resistance is needed in each wall or partition can be challenging, where site fire consultants often have the power to change performance requirements depending on their interpretation of the risk involved.
The situation can become yet more complex, because even when levels of fire resistance are agreed, the required test standards tend to be left to the discretion of the architect, who will generally use either US or UK/European test standards, depending on preference.
Plasterboard systems, for instance, could be specified against US standards – ASTM E119, UL 263 or NFPA 251, for example, or UK/European standards – BS 476 or EN 1364.
Often the biggest issue is ensuring the most appropriate standard is being applied. There can be misunderstandings in the differences between product (manufacturing) standards and system (performance) standards. In terms of fire then, we are commonly aiming to stop the passage of flame, smoke and heat. Whilst it is important that the products used do not add load to the fire [note: highly flammable external cladding panels], in some cases this is confused with a requirement to use a product that only meets a ‘reaction to fire’ performance – ie how that individual product performs rather than a complete system. There can also be confusion around fire resistance versus protecting the building structure, particularly when this is structural steel.
If we are to achieve consistent standards of fire performance in all of our new buildings I believe it is essential we develop the knowledge and understanding of our building designers and specifiers to further understand how fire propagates and moves through structures, and the products and systems that are available to stop and contain fire until the relevant authorities can attend.
Specifiers must be sure that the products and systems they are using meet a wide range of performance requirements. In the case of internal walls and partitions, this means meeting not only fire performance, but a range of other criteria including acoustics, impact resistance and even damp and mold resistance. Gyproc can work with the architect at the early stages of the project to build a complete internal lining specification that meets all of these requirements.
Jason Hird is a senior technical development manager at Gyproc.