In this part, we evaluated relevant properties of glued laminated timber after one year of exposure at the field test site at Department of wood science and technology. For comparison, we tested reference samples that were not exposed to weathering. Glued laminated timber specimens were made of larch, spruce and beech wood. In addition non-glued spruce wood specimens were exposed as well. The glulams were glued with three type of adhesives (PVAc, PUR, MUF) and surface treated (thick layer coating, Silvanolin, Silvacera). We were interested in changing of the mechanical and visual properties of the specimens. The degradation was evaluated visually and accordance with the SIST EN 252 standard. Mechanical properties were determined using the Zwick Roell Z100, universal testing machine. Compressive strength, shear and density of the specimens were determined. After one year of exposure, with the exception of beech wood samples, degradation was not determined. The first grade of the degradation was determined at beech wood samples. One year of weathering resulted in loss of shear strength of glued laminated timber joints, glued with PVAc adhesives (with the exception of samples surface coated with surface coat), on the average declines.