Australia is the most recent country to adopt British Standard BS 8414, in the recently published AS 5113 standard for determining fire performance characteristics and classification of external walls of buildings. The inclusion of the British Standard in AS 5113 adds to the growing international recognition of BS 8414 as a robust means of determining the fire performance characteristics of external cladding systems and follows the recent recognition of BS 8414 in the UAE fire safety codes.
This new AS standard forms part of the Australian building regulations approach to managing the fire safety risks associated with external fire spread on high rise buildings and follows several, widely reported, high profile fires which have occurred in Australia and other countries.
The continually increasing and evolving use of new and innovative products, as part of the external cladding systems on buildings gives rise to concerns for the overall fire performance of the systems as these are often less well understood than those of more traditional materials. The high profile fires illustrate the importance of adequately testing external wall systems exposed to a fire hazard on a realistic scale.
The BS 8414 test methods provide a robust methodology for determining the fire performance characteristics of external cladding systems. The standard is divided into two parts:
Part 1 provides a test method for assessing the fire performance of non-loadbearing external cladding systems applied to the face of the building. This can also be used to test rainscreen overcladding and external wall insulation systems.
Part 2 provides a test method for assessing the fire performance of non-loadbearing external cladding systems fixed to and supported by a structural steel frame.
These test methods were developed by BRE, based on over thirty years of knowledge and extensive research programmes carried out in this field, and were developed to address the challenges of testing and classifying the evolving designs and materials being brought to the market. The test methods were first published as British Standards in 2002 and are carried out in specialist laboratories, such as the Burn Hall at BRE in Watford, where they are performed on external wall systems at full-scale incorporating joints and corner details together with fixings, insulation, fire breaks, cavities and all other elements of the system construction as appropriate. The standard evaluates whether a cladding system – when subjected to a simulated fire in a compartment, breaking out of an opening (such as a window) in an external wall – will result in excessive fire spread up the outside of the building and its potential to re-enter at a higher level. A video of a test to BS 8414-1 at the BRE Burn Hall can be viewedhere.