The Master thesis is focused on summarising the theoretical knowledge about wood-based materials, their use in construction, the need for fire protection by various types of fire retardants, the possibilities of their applicationtheir application and the ability to influence the fire-technical properties of the material which they are applied on.The Master thesis contains an experimental part as well where it was verifying the effect of two retardant coats over the certain time and their comparison. Experiments have demonstrated the effect of these retardants on weight loss of test substances.The final part of the Master thesis is a summary of all results that came from the experiments performed in the period of two and half years. Also processing the assessments where has been proved a positive impact of retardants on fire-technical properties of the OSB board and their persistent effect, even under the influence of aging.