Surface temperature at ignition of wooden based slabs

Up to now, a sufficiently developed ignition theory is not available for wood slabs and other combustible building materials in the form of layers. Very often, the concept of surface ignition temperature as a material characteristic is used, especially when related to fire modelling. Measurements of surface temperature at ignition during cone calorimeter tests for several plywoods and particle board in the horizontal and vertical configurations are presented here. It was found that the surface temperature at ignition depends not only on the material properties but also strongly on the experimental conditions (irradiation, sample configuration). There is evidence that two different mechanisms control ignition in the horizontal and vertical orientations of the samples.