Trä som fasadmaterial ? behandling och beständighet
Since prehistoric time man has used wood to build their environment. The material?s availabilitycombined with its good mechanical properties has often made it the material of choice. Like allmaterials exposed to natures degradative processes the properties of wood decreases over time.Rot, UV radiation and attacks by insects and pests damage wood if not protected. Since we wantwhat we build to consist, optimizing our building materials durability is of great interest.Techniques and methods for increasing the endurance of wood have been developed in severaldifferent places and for a long time. Three reinvented methods to modify wood and its propertiesare heat treatment, acetylation and furfurylation. This work examines the durability problems thatoccur to wood used as façade material, and methods for increasing the durability are identified.By conducting a literature review three, in Sweden only small-scale established, methods ofmodifying wood are being examined. Most of the treatment methods increase the biologicalresistance in exchange for weakened mechanical properties. Modified wood often has similarcharacteristics as conventional pressure-treated wood, why a transition from environmentallyhazardous pressure-treatment to wood modification would be an environmental benefit. Inconnection with the work the design of a single family home was made. By applying the resultsencountered in the work of wood treatments, we found that the most appropriate choice offaçade material for the single family home is furfurylated wood. There is currently no large-scalecommercial production of modified wood in Sweden. Since we have a good access to forests inSweden, there is a strong tradition of timber construction and there are environmental benefits inreducing the use of pressure-treated wood, we see great potential in developing a Swedishproduction of modified wood.