New approach to investigate the suitability of coatings for stable end-use conditions

European standardisation has resulted in prEN 927, which allows to classify, test and categorise exterior wood coatings uniformly. However, the set-up and the value of the standard are highly appreciated in Germany the compliance of a product with this standard can only be regarded as its assurance of minimal requirements. This shortcoming has been evaluated as not satisfying for many wood joinery enterprises and associations to give evidence for a sufficient and guaranteed performance of a coating material applied on wooden joinery. Therefore, a two year research project, which is described in this paper, was initiated by different national industrial and governmental bodies basing on the procedure of prEN 927-parts 2 to 5, with expansion of assessment criteria to provide more accurate representation of practical damage situations. Hence, alternative panel types reflecting on more realistic joinery surface conditions, the influence of mechanical damages and elasticity, the UV-VIS tran smission characteristics, the wet adhesion testing and the mould resistance were included and investigated in great depth in relation to the overal performance of wood coating systems for stable end-use conditions.