Assesses vertical fire spread in external wall systems (cladding, insulation, and rainscreen systems).

As fire propagation to higher floors in high rise buildings is via the outside of the building. The fire exits the incident floor through a window and spreads to higher floors as the flames and thermal plume rise through the effects of buoyancy. This phenomenon has been responsible for a number of devastating fires over the years, therefore, when the risk of vertical fire spread (in terms of likelihood or consequences) is higher, the fire performance of the external wall cladding system must be evaluated as a complete system. This means that all cladding materials and components are assessed collectively as part of the system. Materials used in constructing the building envelope should be designed as an integrated cladding system rather than as standalone items. For this purpose, the term “external wall cladding system” refers to all significant components within the complete wall assembly, including sheet cladding materials, framing, rigid air barriers, insulation, sheet materials or blankets, and internal linings.

Where applicable, the assessment should consider fire exposure from the exterior side of the wall, considering external façades play a critical role in building design. Over the years, numerous innovative systems and materials have been developed to create lightweight, energy-efficient, and sustainable building envelopes. These assembly tests provide information about the combined components for engineers and architects when evaluating façades and also allows façade manufacturers and contractors to evaluate the fire safety risks of a complete cladding system.

Selecting the appropriate test is essential, ensuring it aligns with the requirements of your jurisdiction and is suitable for the specific cladding system being assessed.