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RCI Feb 2018

CLADDING & SHEETING Life after Grenfell: a guide to flame retardant materials for specifiers In this article, Marc van der Voort, managing director of Industrial Textiles & Plastics, discusses the findings of the Hackitt Review interim report and outlines what today’s specifiers need to know when it comes to flame retardancy in The tragic events of 2017 focused the attention of the nation on fire prevention and control in UK buildings. Fire safety testing and evaluation of building materials is ongoing, and UK Building Regulations are now under scrutiny. With new, more stringent standards inevitable, what do today’s specifiers need to know about flame retardant construction materials? Who, and what, is to blame for the Grenfell tragedy? The public inquiry is ongoing, but it will be many months before conclusions are announced. In the meantime, the government published ‘Building a Safer Future – Independent Review of Building Regulations and Fire Safety: Interim Report’ in December last year. In the report, Dame Judith Hackitt, said: “It has become clear that the whole system of regulation, covering what is written down and the way in which it is enacted in practice, is not fit for purpose, leaving room for those who want to take shortcuts to do so.” Lacking in clarity Among the key findings of her interim report are that current regulations and guidance are too complex and unclear, and that the system of product testing, marketing and quality assurance is not clear. Those who commission, design and build a project must all take responsibility for ensuring that buildings are fit for purpose, and 046 FEBRUARY 2018 RCIMAG.COM that “cutting corners” is not acceptable. As Grenfell has demonstrated, this is especially critical for flame retardant building materials. Dame Judith concluded that products must be properly tested and certified, and that the marketing of these materials must be clear and easy to interpret. Those who manufacture the materials used in construction must also take responsibility for ensuring that what they provide to the industry is produced to the highest standards, and that product specifications are confirmed by independent testing and accreditation. Understanding and interpreting The challenge, for both manufacturers and specifiers, is understanding and interpreting flame retardant standards, as well as the testing procedures and protocols used to determine the flammability of a material. British and international building standards specify flame retardant materials for specific installations and structures. Flame retardant additives are incorporated in the materials or added as a coating to make them flame retardant. It is the formulation, quality and amount of these additives, and the equipment used to produce them that determine which flame retardant tests the material will pass and to which standards they will comply. A flame retardant material is one that selfextinguishes; it does not mean that it is flame proof. Flame retardant materials are resistant to catching fire, reduce flammability and inhibit, suppress or delay the production of flames. Flame-proof materials are ones that are not liable to catch fire or be damaged by fire, and are not readily ignited or burned by flames. Today’s regulations Current Building Regulations in England regarding fire safety matters within and around buildings are specified in Approved Document B (Fire Safety) Volume 1 (dwelling houses), and Volume 2 (buildings other than dwelling houses). The documents specify the minimum standards for all materials used in construction, with specific installation requirements (the full document is available online at www.gov.uk). The required standard in Britain is BS 476 (fire tests on building materials and structures) Parts 6 and 7. Part 6 (method test for fire propagation for products) tests the amount of heat given off during a 20-minute test, with measurements being taken frequently to produce an Index result. Part 7 (method of test to determine the classification of the spread of flame of products) measures how far and how fast the flame spreads from the point of ignition over the test time. Materials are rated Class 1 (best) to Class 4 (worst), depending on the spread and speed of the flame. To achieve a Class 1 rating in BS 476 Part 7, the flame must not spread more than 165mm from the point of ignition over a test time of 10 minutes. EN ISO 13501-1 was introduced in 2002 to harmonize the classification of the reaction to fire for building materials. This is also an accepted standard in the UK for Building Regulations, along with BS 476 Parts 6 and 7. Two test standards make up EN ISO 13501-1: EN ISO 11925-2 (ignitability when subjected to direct impingement of flame), and EN ISO 13823 (SBI) (reaction to fire tests exposed to thermal attack by a single burning item). The European standard has a wider scope than BS 476, as it measures flame spread, heat release and toxicity of smoke. Standards across Europe Tests are conducted by, and products accredited by, third-party certification bodies. Because a material has passed a national test, it cannot be assumed that it would have the equivalent Euro Class rating unless the material has been the materials they are specifying Continued on page 48


RCI Feb 2018
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