The development process of a candidate screening test for cladding products

The ongoing cladding crisis within the United Kingdom has elevated the need for designers and risk assessors to have the knowledge and tools to evaluate the fire safety of proposed and existing cladding systems. This paper documents efforts to develop a test that could be used to evaluate the fire safety hazards of cladding products that were either proposed for use in design or that were found on existing buildings. Specifically, the products of interest were composite products (i.e., those comprised of multiple layers). The conceptual approach of the European harmonised system was used as a basis for investigating whether a small-scale test could be used to evaluate product fire hazards. A relevant fire scenario was identified, this was linked to candidate large-scale reference tests, and this was linked to performance in a candidate small-scale test. The candidate test showed remarkable agreement with the reference large-scale test, however, many issues were also identified. It was found that, even when specifically intended to accommodate composite products, the small-scale test was unable to always evaluate hazards. Thus the authors were left with the conclusion—regardless of the testing system, there are always products that will not fit the testing system, however hard one tries.