CONSTRUCTION - MATERIALS TESTING - SOFTWOOD TIMBER GRADING 3

Wane or waney edge ~ occurs on timber cut close to the outer surface of the log producing incomplete corners. Measurement is parallel to the edge or face of section and it is expressed as a fraction of the surface dimension.

Growth rate ~ measurement is applied to the annual growth ring separation averaged over a line 75 mm long. If pith is present the line should commence 25 mm beyond and if 75 mm is impractical to achieve, the longest possible line is taken.

Distortion ~ measurement over the length and width of section to determine the amount of bow, spring and twist.

Distortion ~ measurement over the length and width of section to determine the amount of bow, spring and twist.