Wood is a material that requires many many positive owners, while it is necessary to focus on its effective properties - one of them we also dealt with in our main part of the work and its thermal degradation. The bachelor thesis is focused on the fire protection method of wood and wood-based materials. The topic is processed on a theoretical and practical level. The aim of the bachelor thesis was to compare the effectiveness of retardant coatings (Flamgard, HR-PROOF, ISONEM ANTI-FIRE PAINT and Plamostop D-transparent) applied on samples of spruce wood and OSB boards. Efficacy was monitored by weight shortage and ignition time. By processing the results, which we drew from other authors dealing with the issue of fire protection of wood, we came to the conclusion that each substance fulfilled its role of fire protection, but not at the same level. As a result, we found that the retardants used protected better samples of spruce wood than OSB boards. Of all the materials, Plamostop D - transparent has shown the best ability to withstand thermal stress. During the test, it protected the samples of spruce wood and OSB boards to such an extent that ignition did not occur. The weight shortage compared to the unprotected spruce sample was lower by 75.06% and for the OSB board by 72%. On the contrary, the worst properties were demonstrated by HR-PROF in the OSB board sample, where the difference in weight loss was only 3% and ignition occurred 19 seconds later than in the unprotected sample. We also point out the fact that single-layer coatings are often insufficient and it is necessary to follow the manufacturer's instructions when applying.