Power flux deposition during ELMs and disruptions need to be controlled in ITER to avoid damage to the Plasma Facing Components (PFC). In the present tokamaks, the power and energy deposited on the tile during ELMs is calculated from the surface temperature measurements which are affected by the presence of deposited layers. Thermal behaviour of deposited layer under high heat load exposure has been investigated and thermal properties of the layer have been determined from experimental data and modelling results obtained with CAST3M code.