Accoya will weather naturally
Because Accoya wood has a very high resistance against wood destroying fungi, a popular choice is to use it in various applications uncoated. It will weather naturally to a silvery-gray color, due to physical and biological processes that take place within the top layer.
The rate of weathering, eventual color and level of surface growth will vary according to the amount of UV, elevation on a building, the surroundings, the installation details (particularly those related to ventilation) and the surface texture of the boards. Accoya wood will generally gray at a similar rate as most other wood species, but partial shading of a surface will lead to uneven graying and some visible mold stains, particularly as the initial Accoya color is relatively light and does not camouflage these occurrences in early stages of weathering.