EFFECTS OF CHARRING ON THE DURABILITY OF TROPICAL PLANTATION SPECIES

Abstract

The global shift towards increasing environment awareness has resulted in a surge in the usage of timber in building construction. This phenomenon has led to many industry professionals going back to the roots of timber preservation – Shou Sugi Ban, or otherwise known simply as charring – for reasons being improvements in durability and architectural value. However, research in timber charring has been largely limited to selected wood species, and few existing studies examine the viability of using alternative species for charred timber. With the added need to consider that timber should be sustainably sourced, this paper seeks to examine the impacts of charring on the durability of selected tropical plantation species – Red Jabon (Anthocephalus macrophyllus) and Acacia hybrid (Mangium x a. auriculiformis). Hypothesising that the susceptibility of the chosen timber species to moisture penetration and surface degradation by ultraviolet radiation can be reduced by charring, and further by application of oil finishing, timber specimens of various charring depths – no char, 0.5mm, 1mm and 3mm– were subjected to artificial weathering using an accelerated weathering tester. These specimens were evaluated according to their weight, moisture content, contact angle, L*a*b* colour space analysis, visual changes and hardness. The results of this study proved to be supportive of the hypotheses that charring provides resistance against moisture penetration and offers some degree of protection to decreasing ultraviolet degradation on the specimens. Thus, there is potential in charring these species to reduce their existing susceptibility to moisture penetration and surface degradation by ultraviolet radiation. However, little evidence suggests that the application of oil finishing is beneficial in further reducing such susceptibility due to the limited sample size, lack of information on the chemical constituents of the oil finishing, and various limitations in the design of the experimental setup.