The main causes of damage to wooden structures in historic buildings are the effects of weather conditions and related aging processes. In the case of the roof truss of a 16th-century church in Lubów, the technical condition is additionally affected by leaking roof covering, damaged gutters, downpipes and flashings. Some elements of the wooden structure underwent biological corrosion, which lost its strength values. The roof truss of a 16th-century church in Lubów comes from the period of construction of the building. Due to the historic values of the structure of the truss, the renovation works do not intervene when the works would change its form, shape and type. The truss renovation is based on the assumption of maintaining original construction solutions, location of elements and cross-sections.