Trä-ish : vad kan ersätta trä i konstruktioner i offentlig utemiljö?

Abstract: Wood as a material has traditionally been used and is still used in many constructions in outdoor environments in Sweden. Despite the benefits of domestic materials that do not come from finite resources and have a special character, one cannot ignore the fact that wood requires maintenance. In addition to wear and tear, moisture and UV radiation can lead to the material being affected by decay, which deteriorates the durability so that parts or the entire design must be replaced. The purpose of this paper is to focus on which materials can replace wood in constructions in the public environment and assess these materials based on parameters that take into account everything from the origin of the material to the material's resistance. During our study we have assumed a number of parameters for delimiting the type of information that has been important for both wood and the respective alternative material. In addition to searching for information through literature studies, a questionnaire was sent out to manufacturers and retailers of alternative materials, where the questions are linked to the ones set out in the aforementioned parameters, with the aim of getting a clearer insight into, among other things, production, durability and environmental impact. The answers to the questionnaire were sometimes difficult to interpret and compare. Meetings have been held with the Material Library in Stockholm and the company G9 Landskap, which, in addition to more detailed information on alternative material, has given us the opportunity to both see and feel the materials in person. During the work we have come to the conclusion that irrespective of which material choice is made, both wood or alternative materials have their advantages and disadvantages, within the given parameters. Depending on the type of construction, expected wear and tear and exposure to weather and wind, wood may be suitable in some environments, while the alternative materials have advantages in others. The main advantages of the alternative materials for wood are the long life span, that they do not suffer from decay and that they are almost maintenance-free. At the same time, the work shows that wood is a material that is easily accessible in Sweden, has a greater strength than the alternative materials and gives a warm impression. These benefits can contribute to the use and development of more modification/treatment methods in the future to increase the durability of the wood.