Abstract: There are many kinds of wooden component in timber buildings. This paper conducts burning and flame spread experiments on typical enclosure components, roof components and mortise-tenon components. The fire source with heat release rate of 10 kW is used to simulate the development process of the early fire stage, and the changes of temperature, heat release rate and radiant heat flux are obtained. The results show that with the same heat release rate of the fire source, component size, structure, tree species and fire source location will significantly affect the burning process. For enclosed components, the existence of grille structure makes the timber structure easy to spread flame form double-sided concurrent , and the heat release rate is high, which can be regarded as the key component of the flame spread path in the timber structure fire. For the ceilings in roof components, burning through behavior also helps the flame spread. For Dou-Gong and mortise-tenon components, due to their relatively large size, the flame spread process is relatively slow, but the structural damage of the components may also greatly affect the building. This research provides a reference for identifying the key components in the early fire stage of wooden components.

Key words: timber component, early fire, combustion, fire spread