The role of moisture on the flame extinction potential of Cross-laminated Timber

A significant amount of work has been aimed at determining the design and construction considerations that enable the fire-safe use of Engineered Timber Products (ETPs) by ensuring their flame extinction in the event of a fire. The influence of moisture content in the occurrence of flame extinction has not been studied in depth. In the present work, the outcomes of an experimental study conducted using commercially-available Radiata Pine Cross-Laminated Timber are presented. These experiments aimed at evaluating the influence of moisture content in timber for the full duration of a fire event; from ignition to flame extinction (if any). Outcomes of this work found that higher moisture contents result in higher time-to-ignition and a lower rate of thermal decomposition (evaluated through the sample's mass loss rate). Also, it was found that the critical heating conditions for flame extinction, and its corresponding mass loss rate, are dependent on the moisture content in the material. Finally, the results of this work demonstrate how moisture content for commercially available ETPs can be influential in the design of fire-safe timber structures; more specifically in ensuring the occurrence of flame extinction after fire burnout.