Effect of kerf location on drying quality of larch logs

The demand for structural logs in wooden construction is substantial. However, logs, due to their inherent structural characteristics, are prone to developing checks during drying process. Kerf treatment is a practical and effective pretreatment technology for drying that can significantly reduce checking. Nonetheless, the optimal location for the kerf treatment remains unexplored. This study was designed to position the kerf based on the location of the pith and assessed the effects of single kerf, double kerf, and kerf-center boring treatments on log drying quality. The check ratio of kerf logs decreased significantly (p < 0.05). As kerf depth increased, the check ratio slightly decreased, while the moisture content (MC) difference between the core layer and surface layer increased. Additionally, the inclusion of kerfs in counterpoint positions exhibited a profound effect on reducing the check ratio. Eccentricity influenced the later drying stages of the logs. The check ratio of non-eccentricity logs tended to stabilize during the later drying period, while that of eccentric logs continued to increase. For eccentric logs, this study employed the counterpoint double-kerf process, resulting in a surface check ratio of 0.42%. For non-eccentric logs, utilizing a single shallow kerf significantly improved the surface drying quality, with a surface check ratio of 1.00%.