Chapter 14 - Weathering and surface protection of wood

Abstract

This chapter reviews the Weathering of wood, with emphasis on the causal agents of weathering, the effects of weathering on wood properties and performance, and the protection of wood from weathering. The surface degradation that occurs when wood is used outdoors and above ground is termed “weathering.” The most obvious features of weathered wood are its gray coloration and rough surface texture. While micro-organisms do colonize weathered wood, conditions at exposed wood surfaces do not favor decay. Hence, the defining features of weathering are its superficial nature and the minor role of micro-organisms compared to environmental factors in degradative processes. The chapter outlines the factors and mechanisms involved in wood surface deterioration. The main environmental factors involved in the weathering of wood are solar electromagnetic radiation, molecular oxygen (O2), water, heat, particulate matter, and environmental pollutants. The most common method of protecting wood from weathering is through the use of a wide range of coatings such as paints, varnishes, stains, and water repellents.