This chapter provides the present knowledge on fire dynamics in timber buildings. It summarises the fire behaviour in compartments with a focus on buildings with exposed timber structures and wood linings. It includes basic information on the pyrolysis and charring of wood, along with fire dynamics in compartments and the impact of having exposed timber surfaces. A description of common approaches to characterising post-flashover fires with parametric time–temperature curves is provided with guidance on a simplified design method to account for exposed timber surfaces based on parametric fire curves. Limitations in current knowledge are highlighted.