Reducing Construction Defects and Design Errors in Timber Buildings

Wood is one of our most sustainable materials. It requires less energy to harvest, mill, and deliver to the project location than steel, concrete, masonry, or other materials. Timber products sequester a significant amount of carbon in comparison to the amount of carbon released during harvest, manufacture, and transport. Timber structures have generally performed well in earthquakes and wind storms if constructed according to the building codes and good construction practice. Timber structures often have a cost advantage over other types of structures. These advantages are lost when timber structures fail prematurely and the structure needs substantial repair or replacement early in its life cycle. Many forensic studies have been made of single structures, but these studies have not been performed using consistent criteria or methods nor have the conclusions been examined with respect to other structures. Often authors of these studies at engineering conferences are not experts in wood and fiber science. This paper examines and classifies the types of defects seen in timber structures, and provides recommendations that practicing engineers can use to reduce or control these defects. Learning from the mistakes and the design errors of others are fundamental methods used to improve structural design. Structural engineers of the future need to reflect on the knowledge derived from the past. Lessons learned from these studies can lead to reduced defects in the future and to enhancing the sustainable nature of wood construction. This paper will broaden the knowledge of practicing engineers to assist them to be experts in sustainability and good stewards of materials and the built environment.