Experience with Performance-based Visual Grading of Dimension Lumber

New Zealand produces grades of dimension lumber by both visual and mechanical grading. A system of in-mill quality verification was set up after concern was raised over the changeable quality of visually graded lumber from fast-grown forests. The same systems of quality verification is applied to the lumber regardless of the method of grading - visual, mechanical or a combination of both. Quality records are analysed to show the limitations and effectiveness of the QC system, and of the grading methods.