Fire Performance of EPS ETICS Facade: Effect of Test Scale and Masonry Cover

Many fire disasters have occurred on the thermoplastic expanded polystyrene (EPS) external thermal insulation composite systems (ETICS) installed vertically on the building facade. Thus, it is important to understand the reaction-to-fire performance of EPS ETICS and the effect of sample scale, orientation, and masonry cover in fire tests. In this work, both specimens of EPS alone and EPS ETICS with masonry cover are tested under three different scales, (1) 0.01-m² small-scale cone calorimeter test (ISO 5660-1), (2) 1-m² intermediate-scale test (ISO 14696), and (3) 7-m² larger-scale test (JIS A 1310). Results show that the impact of sample orientation is important, because the heated vertical EPS can melt and flow away without ignition, and the masonry cover limits the flow of EPS melts. The peak heat release rate per unit area (pHRRPUA) in the small-scale test doubles that of the large-scale facade test with a vertical flame spread, so that it cannot be simply scaled up. Moreover, the masonry cover on the EPS ETICS can significantly reduce the burning rate and HRR by a factor of 50%, and it is effective from small-scale to large-scale fires. The embedded rock-wool fire barrier inside the EPS ETICS can significantly reduce the vertical flame-spread rate and HRR. This work helps understand the scale-effect of facade fire test and quantifies the effect of masonry cover on lowering facade fire hazards.