The paper presents experimental studies of bending heterogeneous pine beams reinforced with jute fabrics. Pinus Sylvestris L, a Scandinavian wood species, was used in this study, originating from discard, subjected to 5-year atmospheric influences and biological degradation. The use of recoil wood is an excellent choice, forced by the increasing shortage of high-quality assortments and the need for economical management of scarce raw material. The article presents experimental results regarding the effectiveness of pre-stressed jute reinforcements in the tension zone of pine wood. The effects of using jute fabrics in beams were analysed, and the results were compared to beams without reinforcement. Additionally, the aim of the research is to investigate the influence of jute fabrics on the ductility of wooden beams. Research has been conducted on these polymer composites reinforced with natural fibres due to environmental awareness, their many advantages and, above all, the fact that they are sustainable materials. The conducted tests revealed that the jute fibres had a positive impact when applied to wooden beams and the load-bearing capacity increased by 24% and stiffness 24% compared to unreinforced beams. Moreover, the tests confirmed enhanced strength (24%) of reinforced pine beams in relation to the reference beams. In contrast, the ductility increased from 6.6% for reference beams to 75.7% for reinforced pine wood. Reinforcements with jute fibres have considerable ductility, which indicates that jute fibres are an excellent material for reinforcing the structure.