Flammability trends for a comprehensive array of cladding materials

The flammability of materials is a key component of modern cladding fires. Vertical flame spread is a complex phenomenon which is, amongst others, a function of thermal inertia, ignition temperature, and heat release. The recently published Cladding Materials Library contains the needed flammability data to help engineers perform fire risk assessments on buildings. Cladding fire research has previously generally focused on expensive and time consuming full-scale testing, or on the chemical composition, with little regard to the flammability or other performance metrics. This research shows common trends in the ignition and burning behaviour for cladding materials in a systematic bench-scale study using the Cladding Materials Library. The organic content is shown to be a poor indicator of the fire performance, as represented by the heat release rate. A simple and highly conservative model indicates the relative behaviour of a diverse range of cladding materials. This analysis supports competent engineers to select which specific buildings require further investigation based on performance, and to aid development of remediation solutions. The differences within categories of materials, e.g. high-pressure laminates, are large and thus the performance should be tailored for the specific building material. This work complements but does not replace full-scale system testing. •Organic content is shown to correlate poorly with fire performance.•Residue in an inert atmosphere may be useful for rapid screening purposes.•Cladding materials within generic categories behave very differently.•Specific cladding materials with potential low flame spread are highlighted.