In this study, vermiculite, which is used as a mineral material for thermal and insulation purposes, was added to rigid polyurethane material and used in the surface coating of two different wood composite materials. Vermiculite was added to the total polyurethane mass by 5% and 10%. In the study, medium density fiberboard (MDF) and plywood were used as wood composite materials. The combustion behavior of wood composite materials coated with rigid polyurethane was examined in accordance with TS EN ISO 11925- 2 standard with single source flame test and mass loss and thermal permeability values according to DIN 4102 and TS en 13823 standard. In addition, surface hardness and electromagnetic shielding properties of the materials were determined. According to the experimental results, it was determined that vermiculite additive in wood composites whose surface is covered with polyurethane contributes positively to the combustion resistance of both materials. While surface hardness gives good results in plywood materials, it is determined that mass loss and thermal permeability values give better results in MDF materials. In the experiments, it has been observed that as the ratio of vermiculite at the measured frequencies increases, the electromagnetic shielding property also increases.