Abstract
Wood, as a building material, is nowadays more often used outdoors. From the point of view of environment care, wood constructions and use of renewable materials belongs between modern increasing trends in industry. Wooden facades, more often used without surface treatment, are the important part of this trend. In Central Europe, European larch (Larix decidua) and Siberian larch (Larix sibirica) are especially popular materials for wooden facade elements. The aim of this study is to characterize the surface degradation of untreated facade models from both European and Siberian larch wood. The wood species, orientation to the sides of the world and construction type of the facade were the evaluation factors, which were regularly examined during 24 months of outdoor exposure via measuring the changes of surface colour, gloss, wettability and visual appearance in the form of cracks and resin leaking. The influence of all evaluated factors on the measured properties was determined. The results of this work can help to proper use of untreated larch wood on facade elements in practice.