27 May 2008 15:51pm

Are you Specifying the best when it comes to Fire Resistance

Fire Engineering, Fire Safety, Industry News, LPS1181, Non-combustible, PIR

“Specifiers are being increasingly directed towards composite panels with a non-combustible core”, says Richard Wigley, Marketing Manager for Eurobond.

The Fire Safety Order 2005 for the first time officially recognised the risks associated with combustible composite panels. The accompanying guides on fire risk assessment and fire precautions state: “The potential for fire development involving stone wool cores is less than that for composite panels containing polymeric cores. Therefore, in areas where there is a considerable life risk, it may be appropriate to consider replacing combustible composite panels.”

The draft of the NHS FireCode goes even further, stating, “Selecting the appropriate insulated core products for internal walls or partitions, or for external cladding material is vital for patient and building occupant safety…Wherever possible cladding with a non-combustible core should be used.”

So why is the distinction between combustible and non-combustible cores now such a focus? It all comes down to some confusion in the market as to the level of fire protection that is actually achieved by the different types of composite panel available. Indeed, some manufacturers will claim they offer ‘non-combustible’ building systems based on the premise that when first exposed to fire they will not burn immediately and this is extremely misleading. Plus, the only universally recognised standards for fire performance in this sector aren’t fully understood and do little to help the confusion.

Many specifiers look towards Loss Prevention Certification Board (LPCB) LPS 1181 testing when assessing the contribution to fire growth of different composite panels. However, just because a composite panel system meets LPS 1181 testing this certainly doesn’t mean it is non-combustible.

In addition, few realise that there are actually two grades of LPS 1181 – Grade EXT-A and Grade EXT-B. In fact, independent research commissioned by Eurobond found that less than 15% of specifiers looked for Grade EXT-A specifically when assessing fire performance, and yet it is an extremely important differential.

Some composite panel manufacturers may say that they have LPS 1181 and yet they are only referring to Grade EXT-B, a ‘reaction to fire’ test with no measure of ‘fire resistance’.

For a product to truly offer protection in relation to ‘fire resistance’ rather than just ‘reaction to fire’ it must resist the transfer of heat from the exposed to unexposed face and retain its integrity.

This performance is tested under LPS 1181 Grade EXT-A, which involves the system not only undergoing the basic LPS 1181 test, but also demonstrating it is fire resistant in accordance with BS476 Part 22, the standard for the Methods for Determination of the Fire Resistance of Non-Loadbearing Elements of Construction.

BS476 Part 22 simulates the post-flashover stage of a fire through to a fully developed fire, sustained for the duration of the test. This is crucial in determining a composite cladding system’s true fire performance, as once a fire is fully developed it is likely that the steel faces will expand, buckle and open the joints to expose the most vulnerable component, the insulation core. It is therefore vital to understand what contribution to fire spread a system may make at this stage, to ascertain fully its fire resistance.

For example, composite panels that have been manufactured using a non-combustible core such as stone wool will never ignite in the event of a fire, as the material is made of stone and will not burn. The panels therefore contribute no additional risk of fire spread or smoke.

The same can’t be guaranteed for foam cored panels such as PIR, which according to BRUFMA (British Urethane Manufacturers Association) will ignite at around 450°C. With temperatures hitting 900-1000°C in a typical post-flashover room fire the risk of fire spread is therefore very real, if combustible cored panels such as these are in use.

The risks associated with panels manufactured using a combustible PIR core, has long been the reason behind Eurobond championing non-combustible stone wool cored composite panel systems, and Eurobond’s Europanel™ and Firemaster™ products are both ideal for hospital design, principally due to their superior fire performance.

Additionally, Europanel’s™ design flexibility ensures the aesthetics needn’t be compromised. Module sizes are available from 300mm – 1200mm in 5mm increments, enabling feature bands to be provided in relatively small quantities plus alignment of the panel joints with window heads and cills. Europanel™ also offers consistent and high quality architectural flatness with secret-fix joints to improve building aesthetics and create clean, uninterrupted facades well suited to landmark buildings, such as hospitals.

For internal fire partition walls, Eurobond Firemaster™ can offer up to four hours resistance, vital for the compartmentation of a building, creating protected zones and enabling safe evacuation. Firemaster™ can also be supplied faced with Corus Colorcoat ® , designed to offer the very best resistance to both physical and chemical damage in healthcare environments, and protect against the spread of MRSA and other hospital acquired infections. Eurobond Doors also supplies the Euromaster Fire Doorset Range, which has been fire tested and assessed by the Warrington Fire Research Centre and offers 60, 120 and 240 minutes fire resistance and compliments the Firemaster panel range.

Now more than ever specifiers need to consider the contribution building materials may have on fire spread or smoke, especially within school and hospital projects. The message is simple – when it comes to fire why take the risk? Only non-combustible composite panels offer true levels of fire and smoke resistance.

_{Colorcoat, Colorcoat HPS200 Ultra, Confidex and Confidex Sustain are trademarks of Corus.}