This paper presents a numerical model for heat transfer in timber structures. The thermal behaviour is described by the standard Fourier heat equation. The chosen model integrates the three modes of heat transfer; namely: conduction, radiation and convection during the fire exposure. The theory and the boundary conditions associated with the model are briefly discussed. The identification of the model parameters is carried out with the experimental data available in literature. The simulation results are compared with experiments carried out on laminated veneer lumber (LVL) panels.