Book excerpt: This monograph discusses fire hazard and fire resistance in wooden structures with a long duration of operation. Aside from its increasing importance for modern architecture, wood has been the most important building material in the past. It has a distinct aesthetic, high mechanical strength, and resistance against many environmental changes. These properties are evident in structures like the still standing Grinstead Chuch, which has been built in 1045. Readers will however learn about the decreasing fire resistance in wooden buildings with a long service live. Considering the cultural value of medieval wood buildings, this topic becomes increasingly relevant. The chapters discuss the mechanical, physico-chemical and thermophysical properties of wooden structures over different lifespans. Many factors contributing to the changing fire resistance in the ageing process of wooden structures, are explained. This book is a valuable resource for students, teachers and scientists in the areas of wood science, fire research and forestry.