Performance of Exterior Wood Coatings in Temperate Climates

Wood used in exposed exterior applications degrades and changes color due to weathering. Expanded use of mass timber is resulting architects increasingly designing structures with wood exposure. Coatings can reduce the effects weathering prolong visual characteristics wood. However, coating performance depends on a variety factors including blend resins, oils, pigments, binders. Coating manufacturers often claim superior for products, but data directly comparing different coatings species rarely publicly available. Premature failure increases long-term building maintenance expense while potentially enhancing biological degradation reducing service life. This study compares 12 5 species. Performance was evaluated according components International Commission Illumination (CIE) L*a*b* space images taken at 6-month intervals over 18 months samples. The analysis performed using Welch’s ANOVA, Games-Howell pairwise comparisons tests, clustering procedure distances between each pair groups means ?L*, ?a*, ?b* values. Most lost their protective within 1 year exposure combinations ultraviolet radiation (UV) illustrating difficulty protecting exposures. provides guide users wishing specify structures.