The main purpose of this paper is to analyze the results obtained during the conducted tests of the pull-off strength of a CFRP composite glued to pine beams made of glued wood previously subjected to destructive tests. Three research methods were used in the tests to determine the CFRP composite's pull-off strength from the wooden beams' surface. In this research the Authors experimental method was used, PN-EN 1542 and ASTM C1583 standard. Pearson linear correlation analysis allowed to identify the relationship between the forces that destroyed the beams and their pull-off strength. The assumptions of the experimental method, description, and preparation of the samples for testing, the course of testing, the method of applying the pull-off force, and the types of substrate destruction were considered as well. The conducted tests showed that the most common causes were detachment of the composite layer from the wood, cohesive destruction in the substrate of the tested elements, and adhesive destruction between the adhesive layer and the disc, which were not determined in previous studies.