In the bachelor's thesis, we focused on a very current area in construction, namely insulation materials. More specifically, we have chosen the area of facade and roof thermal insulation, as nowadays more emphasis is placed on increasing thermal insulation comfort in either existing buildings or new buildings. We divided the bachelor thesis into two parts, namely the theoretical part and the practical part. In the theoretical part, we described the issue, summarized the knowledge of the most commonly used thermal insulation materials in terms of their properties and use in construction and briefly described the test methods for evaluating and classifying building materials in terms of reaction to fire. In the practical part, we evaluated an experiment in which we tested the insulation materials of the Slovak insulation manufacturer Knauf Insulation according to the test method STN EN ISO 1182. According to the results we obtained, we classified this material in the reaction to fire class A2. In the end, we compared the obtained results with the technical specifications given by the manufacturer and the results of research by other authors of theses who dealt with similar issues.