Knowledge gaps and fire behavior of deadwood

The reuse of salvaged and deadwood timber represents a promising yet challenging opportunity within a circular construction framework. Deadwood is an abundant resource whose mechanical and thermal responses are significantly affected by ageing, environmental degradation, and prior exposure conditions. These factors may alter density, moisture transport, and chemical composition, leading to fire behavior that differs markedly from that of new timber. Moreover, reclaimed wood is frequently subjected to conditioning or stabilization treatments, such as drying, hydrothermal vaporization, or saline impregnation, whose implications for fire resistance are still poorly understood. This paper reviews the current state of knowledge on the thermomechanical behavior of aged and treated wood under fire exposure, with a particular focus on the mechanisms governing ignition, charring, and post-fire strength degradation. The work highlights the scientific and technological gaps that must be addressed to ensure safe and reliable reuse of salvaged timber in structural applications. By mapping available data and identifying research priorities, this study aims to establish a foundation for future experimental and modelling investigations supporting the sustainable valorization of deadwood in a sustainable built environment.