Evaluation of Untreated and Surface-Treated Wooden Facades of Buildings in Sweden

In this research, untreated and surface-treated wooden facades of buildings are investigated and compared with regard to durability, environmental impact, and cost using the document and literature studies supplemented with quantitative data. The investigation is based on the influence on the wood by external factors, either in its natural form or with a protective layer of a surface treatment. It is resulted from the study that from a durability viewpoint, it is not always advantageous to paint a wooden facade. Yakisugi, a thermal modification for wooden facades that involves burning the wood to create a protective surface layer, has shown better properties, which, in combination with a lower need for maintenance, can be considered the leading treatment for facades. From an environmental perspective, Yakisugi, like untreated wood, has demonstrated advantages compared with conventional paints. Paints often come with maintenance requirements that should be carried out correctly to avoid extensive costs. Cost is an important factor that can be decisive when users choose a surface treatment. What determines the cost is the relationship between durability and maintenance intervals. The need for the maintenance of paints leads to large financial costs during the working life of a wooden facade, which differs from Yakisugi or an untreated wooden facade that can be considered maintenance-free. In order to meet the growing environmental demands from a national level to a global scale, unconventional surface treatments for wooden facades should be promoted in the future.