Experimental study of expanded polystyrene (EPS) External Thermal Insulation Composite Systems (ETICS) masonery façade reaction-to-fire performance

External Thermal Insulation Composite Systems (ETICS) consisting of insulation core and decoration surface materials, are quite common in new constructions and refurbishment buildings with design-oriented goals of sustainability and energy efficiency. However, combustible insulation core has caused serious result due to the ravages of fire disasters. Thermoplastic expanded polystyrene (EPS) acting as an insulation core is widely and vertically installed in ETICS. Presently, with an aim to evaluate EPS ETICS fire performance, a series of EPS ETICS specimen varying EPS thickness from 50 mm to 300 mm, polymer mortar type including SBR polymer mortar and acrylic resin mortar, reinforcement including one layer and two layer's glass fiber mesh, and opening edge treatment method differs from back-wrapping method to fire barrier method are tested by a large-scale Japanese façade fire propagation method JIS A 1310 with heating intensity from 100 kW to 1100 kW. A comprehensive fire risk evaluation INDEX method of EPS ETICS based on EPS burn area and façade surface temperature profiles of JIS A 1310 tests is proposed. It could easily classify the effects of mortar, reinforcement, EPS thickness and opening edge treatment method on EPS ETICS fire performance. It is concluded that in JIS A 1310 method, the fire risk of EPS ETICS could be classified by INDEX method as the followings: the INDEX ≤ 0.825 is an acceptable level; the INDEX ≥ 0.836 is the unacceptable level; 0.825 ≤ INDEX ≤ 0.836 is the critical level. The fire propagation index (FPI) is believed to be a potential prediction method for EPS ETICS fire risk evaluation before JIS A 1310 tests. The FPI is classified as the followings: the FPI ≤ 17.3 is an acceptable level; the FPI ≥ 21.4 is the unacceptable level; 17.3 ≤ FPI ≤ 21.4 is the critical level.