In the construction process of our CLT modules, we use facade layers compliant with the standards required for homes intended for year-round occupancy. These layers serve as thermal and acoustic insulation and protect the walls from the outside. Thus, CLT panels are not exposed to external weather conditions. Wooden boards or facade panels are used as the final (external) layer of cladding.

However, if CLT wood is subjected to prolonged exposure to weather conditions, its outermost layer will respond like any other wood. Under the influence of precipitation and high humidity, wood alternately swells and shrinks. This phenomenon is known as volumetric fluctuations. These fluctuations are exacerbated by temperature changes and can lead to the formation of micro-cracks. Unlike traditional wood, however, CLT sections do not lose their structural strength due to this process. Nevertheless, the formation of gaps between the lamellas of the outermost layer may affect the visual properties of a CLT wall. Additionally, exposure to UV radiation causes oxidation of the wood’s surface layers, resulting in color loss or a bluish tint.

For these reasons, we do not recommend using CLT as a layer exposed to atmospheric conditions for longer periods. If a client wishes to use CLT for elements such as a pavilion, the CLT elements should be protected with traditional wood preservation treatments.