Stress/Strain Behaviour of Mechanical and Adhesive Joints in Timber Façade Applications

This paper compares the stress and strain behaviour of mechanical fasteners and elastic adhesive connections in timber façade applications. Two common designs with timber cladding are introduced. The traditional façade planks and multilayer large-format solid wood panels were selected. The resistance of a reference façade section with mechanical fasteners or adhesive bond to wind suction is determined according to the recommendations of European guideline ETAG 034. The pressure/suction chamber allowing hermetic closure was used. The sample deformation was measured at 15 locations, this also allowed to determine the elongation of the adhesive layer at break. The failure loads reached with the adhesive joint exceeded 20 kN/m2in both combinations of façade cladding. On the other hand, the sample with a large-format panel and mechanical fasteners showed the lowest failure load at 12 kN/m2. The results confirmed that bonded joints are a suitable solution for large-format cladding, whereas an increase in the number of mechanical fasteners will be a more convenient solution for façade plank applications.