A weathering study in Germany and New Zealand - implications for development of an international standard for the weathering of wood coatings

The weathering of typical used coatings on pine sapwood in Germany and New Zealand has been evaluated in a comparative weathering trial. The New Zealand site had a climatic index 50 % more challenging. Significant differences in performance relating to coating, species, sites and exposure are presented. The coating and site had most significant effects, while species had least. A solvent borne stain and a hybrid paint qualified for stable end-use situations in both countries. An acrylic paint performed better in Germany while an alkyd gave the poorest performance of the four coatings tested. More effective fungicidal coating properties are required in New Zealand to suppress mould growth. Areas of deficiency for internationalising the European weathering standard EN 927 are discussed.