The façade of every building is subjected to the influence of different weather conditions such as rain, hail, snow or sun.
Chemical protection is not required. Due to weather conditions, the surface of larch changes colour and structure acquiring a grey patina. It is a natural process occurring with any kind of wood used for façades and its effect is merely aesthetic as it by no means influences the functionality or the façade durability.
If maintaining larch natural colour is desired, we recommend using exclusively thin-layered and colour-free coatings based on organic dissolvents. At least two coatings are necessary but three are recommended.
Such coatings absorb easily even if used on larch wood already exposed to weather conditions. The spread on the surface enables wood to breathe and provides limited UV protection. Thin-layered colour-free coatings should be used every two to three years while annual coating control is recommended.
Thick-layered and pigmented coatings are not appropriate for larch as they additionally heat the surface and can cause the appearance of dark spots and bubbles due to the discharge of resin and other compounds.
When it comes to spruce, its chemical protection is determined. The first coating of chemical protection is impregnation, which prolongs the duration of wood and protects from rotting and mould. Three thin water–based coatings follow the impregnation layer. Thin-layered coatings should be renewed every three to four years, depending on the building position and climatic conditions, and annual control is recommended.