Wood, as one of the oldest building materials, is popular for different types of structures. As a natural resource with hygroscopic behavior, its strength, durability and visual appearance is highly affected by changing climate conditions. Those factors can significantly influence the durability and estimated age of climate exposed buildings and structures. Reversing or stopping degradation of the structures and their mechanical properties is of utmost importance when members or other parts of the structures need to carry loads or serve for overall structural stability. To gain a better understanding of the environmental, aging and degradation impact on climate exposed timber structures a field study on the influence of natural aging and degradation of wood species has been started to serve for determination of prerequisites for strengthening or refurbishing of treated or matured wood in reconstruction. First, a better understanding of the influence of natural hazards like climate and weather exposition or fungi attack on exposed wooden parts in historical buildings is needed to evaluate the degradation level depending on the intensity over time. With this knowledge, a repair technique based on a resistance-enhancing surface treatment shall be developed with an adhesive strengthening system based on permanent coating.