Expanded Polystyrene (EPS) Larger-Scale Fire Testing Series: BS 8414-2 Reaction-to-Fire Test Reports and Videos – Cladding Safety Victoria

This record contains three reaction-to-fire test reports for the Expanded Polystyrene (EPS) Larger-Scale Fire Testing Series, commissioned through Cladding Safety Victoria (CSV), together with associated shortened videos. Each video relates to a corresponding test report and is intended to complement the written report. CSV is the Victorian Government program responsible for addressing combustible cladding risk in Victoria and improving industry understanding of the fire performance of cladding products identified on buildings referred to the program. The CSV cladding testing page states that the testing program is intended to increase collective understanding of the performance characteristics of different cladding types and the degree of fire risk they may pose.

Expanded Polystyrene, or EPS, is a lightweight rigid polymeric foam derived from styrene. When used as external cladding, EPS is commonly covered with a render system for protection and finish.

The testing forms part of CSV’s broader cladding product fire testing program. CSV’s testing is scenario-based and evidence-driven, with tests tailored to reflect specific building configurations, realistic fire exposures and wall-system components observed across CSV’s portfolio, rather than relying solely on a product rating, classification or pass/fail outcome. The reports should be read as technical evidence of performance under the specific tested conditions, and not as standalone certification, compliance confirmation, or a universal assessment of all EPS wall systems.

The three larger-scale EPS tests used the BS 8414-2 heat source and larger-scale wall arrangement as a defined external fire exposure scenario to examine the fire behaviour of rendered EPS facade systems. The test specimens used 75 mm pre-rendered EPS fixed to timber studs, with glass wool insulation selected to reflect lightweight, low-rise, timber-framed apartment construction commonly observed from the 2000s. The render system applied to the EPS was approximately 4–5 mm thick and included a polymer-cementitious base coat, acrylic primer, acrylic texture coat and waterproofing membrane. Additional instrumentation, including internal and external thermocouples and plate thermometers, was used to capture temperature development, fire spread pathways and wall-system response beyond visual observations.

All three tests involved a main wall measuring approximately 5.715 metres wide by 3 metres tall, and a wing wall measuring approximately 5 metres wide by 3 metres tall, with a 2 metre by 2 metre chamber opening offset 500 mm from the face of the wing wall. Test 1 involved the base specimen configuration. Tests 2 and 3 introduced a 1 metre wide by 3 metre tall return wall and a vertical non-combustible aerated concrete cladding section on the main wall, positioned approximately 1.8 metres from the combustion chamber side wall.

The reports and videos provide a technical record of the rendered EPS façade system’s behaviour under the specific larger-scale fire test conditions. They describe the test setup, specimen construction, installation details, instrumentation, temperature measurements, visual observations, post-test observations, drawings, test data and photographic evidence. The reports record observed fire behaviour including horizontal flame spread, the performance of the rendered EPS system, and the effect of the vertical non-combustible firebreak configuration used in Tests 2 and 3.

The reports should not be read as standalone certification, compliance confirmation, or a universal assessment of EPS products or wall systems. Rather, they provide practical, test-based evidence of how the tested rendered EPS façade systems performed under defined BS 8414-2 exposure conditions. The information can assist broader risk evaluation and decision-making for materially similar products or wall-system configurations, provided that differences in installation, render system, wall framing, insulation, cavity conditions, firebreak design, fixings, fire exposure conditions and other construction details are carefully considered.