Fire safety of rendered expanded polystyrene (EPS) in Exterior Insulation Finishing Systems (EIFS) on Class 2 to 9 buildings of Type A or Type B construction
What we did and why
The VBA has heard differing opinions from the building industry on the fire behaviour and risks associated with the use of rendered EPS (with fire retardant) in EIFS on Class 2 to 9 buildings of Type A or Type B construction.
We engaged the Commonwealth Scientific and Industrial Research Organisation (CSIRO) to conduct a literature review on EPS in EIFS and Insulated Sandwich Panels (ISPs) on Class 2 to 9 buildings of Type A or Type B construction. The literature review identified, among other things, the lack of publicly available test or other evidence about the façade fire spread performance of this product when installed in Australia in Class 2 to 9 buildings of Type A and B construction.
We subsequently commissioned an independent full-scale fire test to test the fire spread performance of EPS (with fire retardant) in EIFS on Class 2 to 9 buildings of Type A or Type B construction.
The test was conducted by a National Association of Testing Authorities accredited laboratory (Warringtonfire Australia) in June 2020 and witnessed by the CSIRO. The test system was built as representative of typical rendered EPS (with fire retardant) in EIFS on Class 2 to 9 buildings of Type A or Type B construction in Victoria and was conducted in accordance with AS 5113:2016 Classification of external walls of buildings based on reaction-to-fire performance - External Wall (EW) classification test.
What we found
The rendered EPS (with fire retardant) in EIFS as tested failed to meet the AS5113 EW classification acceptance criteria. The test results provide a clear indication that the use of rendered EPS (with fire retardant) in EIFS would result in rapid vertical fire spread and pool fires when exposed to a large fire source, such as from a window opening or an external fire source.
Furthermore, it was concluded from the testing that rendered EPS in EIFS has a similar propensity for vertical fire spread to aluminium composite panels (ACP) cladding with 0% inert filler (commonly described as 100% polyethylene core) wall systems when exposed to large fire sources.
What difference this made
The test results validate the careful approach taken to date by the Statewide Cladding Audit and its risk mitigation strategies to protect occupants in Class 2, 3 and 9 buildings.
The findings of the literature review and façade test informed a VBA Industry Update (PDF, 552.42 KB) on the fire safety of rendered EPS (with fire retardant) in EIFS on Class 2 to 9 buildings of Type A or Type B construction. The VBA directly shared the Industry Update, literature review and test reports with key industry and government stakeholders, and with industry and practitioners more broadly in December 2020.
Note: The Minister for Planning announced a prohibition on the use of the external wall cladding products ACP and EPS for any building work in connection with buildings of Type A and Type B construction, effective 1 February 2021. The VBA has prepared an Advisory Note (PDF, 489.95 KB) about this prohibition.
Building occupants in Class 2 to 9 buildings of Type A or B construction who suspect that their building has combustible cladding should speak to their owners corporation or building manager to discuss if the building has been audited and familiarise themselves about information on combustible cladding.
Building occupants in Class 2 to 9 buildings of Type A or B construction should speak to their owners corporation or building manager about fire safety and ensure the building’s Essential Safety Measures (ESMs) are properly maintained. The VBA website has further information on maintenance of ESMs, including the In Safe Hands podcast. To reduce the risk of fire, building occupants in Class 2 to 9 buildings of Type A or B construction should follow the Fire Safety on Balconies (PDF, 808.93 KB) advice for balconies and high-rise apartment buildings.
 Class 2 to 9 buildings are multi-storey residential buildings, office or other commercial buildings, factories, warehouses, and public buildings such as hospitals and schools.
 A building’s construction ‘Type’ describes the level of fire resistance that certain parts of buildings need to have. There are three Types of construction (A, B and C), which are determined by the building’s use (e.g. its building class) and the number of storeys in the building. Type A buildings have the highest risk and are required to be the most fire resistant. Type C buildings have a lower risk and are generally the least fire resistant.
The views and opinions expressed in the CSIRO literature review and report, and the Warringtonfire reports, are those of the authors and do not necessarily reflect the views of the Victorian Building Authority.