The prediction of the cause of a fire, thus the spread of it, is one of the major challenges in fire safety science. It allows to determine the dynamics of the fire under consideration of the relevant physical and chemical processes, and especially the behaviour of the burning material. We conduct experiments on the micro scale to understand the pyrolysis of the material, i.e. the thermal decomposition, to determine the relevant material parameter. With these, we utilise computation fluid dynamics models to predict the flame spread in large scale experiments.