Exterior facade fires become an increasingly worrisome international problem
BY DONALD P. BLISS
In every country I’ve visited recently for NFPA, fire protection professionals are discussing fires involving improperly tested exterior façade assemblies on high-rise buildings. They agree that there is no easy solution to correct this unsafe condition in hundreds, if not thousands, of existing high-rise buildings worldwide. They also agree that, while it is fortunate that no loss of life has occurred in these fires, it is only a matter of time before an exterior façade fire extends into a building, trapping occupants and firefighters.
The root of the problem is a combustible foam plastic material—polyurethane foam and extruded polystyrene are most commonly used—that makes up the core of non-load-bearing exterior walls in these otherwise noncombustible buildings. The foam and its accompanying substrate materials provide insulation and a weather-resistant barrier intended to provide energy savings, aid compliance with energy codes, and prevent water penetration. Notable fires involving these materials have occurred in China, Australia, the United Arab Emirates, and Korea, with the most infamous being the New Year’s Eve 2015 fire at The Address hotel in Dubai, UAE. The 63-story tower became engulfed in flames when a spotlight short-circuited on the building’s façade.
Until now, automatic fire sprinkler systems have been credited with checking the interior spread of these fires and providing time for occupants to escape. But any number of future scenarios could have catastrophic consequences, such as a fire in an unsprinklered high-rise, a failure of the sprinkler water supply, an improperly maintained sprinkler system, or a fire of such magnitude that it overwhelms the sprinkler system.
NFPA 285, Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Non-Load-Bearing Wall Assemblies Containing Combustible Components, regulates the use of combustible materials in exterior walls in all construction types, and is intended to be adopted or referenced by model building codes such as NFPA 5000®, Building Construction and Safety Code®. NFPA 285 provides a standardized fire test procedure for evaluating the suitability of components used in exterior non-load-bearing wall assemblies and panels. Without a strict regulatory system, though, ensuring compliance with NFPA 285 is difficult. Oversight must include direct reference or adoption of NFPA 285, licensing or accreditation of design professionals, comprehensive plans review, and in-progress construction inspections. Ideally, independent third-party certification of the exterior façade assembly should also be required to ensure that substandard products have not been substituted after the initial plans review and approval process has been completed. It is also important that the proper test protocol has been conducted on the assembly.
In 2014, the Fire Protection Research Foundation released a report on the issue that included test protocols and code requirements of various nations. The Foundation plans to develop related research projects and an assessment methodology for existing exterior combustible façades.
Even so, much work remains to create mitigation strategies for planned and existing buildings utilizing these assemblies. Developing nations are particularly at risk of exterior façade fires due to unregulated urbanization and unprecedented high-rise construction. The stark reality is that jurisdictions without modern building codes and effective regulatory systems have a high potential to experience large-loss-of-life fires if nothing is done to address the problem.