Hardwood Log Grading–A Phase of Quality Control

Ideally, quality control in the wood-using industry should begin with genetic management and silvicultural practices; practically, it must begin with the mature tree. Quality control is largely dependent on selection. The supply of good lumber is decreasing. Several psychological problems are unique to the log and timber marketing process. Instead of being bought over the counter by the piece or pound, timber and logs are traded, with the buyer and seller depending on each other’s knowledge. Methods of measuring timber quality are not precise, and the value of a piece of wood is not constant, nor is the wood itself homogeneous. There is often no time or equipment for the cumbersome job of applying quality standards. Technical difficulties arise from the conflicting use possibilities for a log and the lack of adequate published technical information on the factors affecting quality. Adoption of a definite working system is suggested. Sawn and veneer products are given priority in production, with these divided into sawlog and saw-bolt classes, and the remaining timber separated into classes– factory lumber, structural lumber, local use lumber, and others. Grades are used to further separate the logs in each class into value groups. A system of grading must be based on externally measurable characteristics, it must work with small quantities of logs, and it must be learnable. Practical suggestions for finding published information on log grading, applying grades to lumber and standing timber, learning log grading, and checking grades against values are given.

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