Effect of protective cladding on the fire performance of vertically loaded cross-laminated timber (CLT) wall panels

ABSTRACT  Cross-laminated timber (CLT) is a sustainable engineered wood product which is utilised in modern multi-storey timber buildings. The fire behaviour of timber structures is often a concern due to their combustible nature. In this paper, experimental fire testing of CLT panels made of Irish spruce was performed. This series of tests consisted of four vertically loaded CLT wall panels which were tested under Standard fire curves in the Structural Laboratory of Munster Technological University, Cork (MTU). To improve the fire performance of CLT panels, different types of protective claddings were used. The effectiveness of each system of protection has been stated particularly in terms of the delay in the start of charring of the CLT panels. The location of joints in the protective cladding was also analysed and was found to be a key factor in the fall-off time of the protective claddings. The results show that protective claddings made with Fireline gypsum plasterboard and a combination of plywood and Fireline gypsum plasterboard delayed the charring of CLT panels by as much as 30 and 44 min respectively. This paper analyses the detailed results of experimental fire testing and measures the charring rate and temperature distribution across the panels.