CONSTRUCTION - MATERIALS TESTING - SOFTWOOD TIMBER CLASSIFICATION

Grading ~ either visually or by computerised machine. Individual rectangular timber sections are assessed against permissible defect limitations and grade marked accordingly.

UK grading standard ~ BS 4978.
European grading standard ~ BS EN 14081 (4 parts).

The two principal grades apart fromrejects are,GS (general structural) and SS (special structural) precededwith anMif graded bymachine.

Additional specification is to BS EN 338: Structural timber.
Strength classes. This standard provides softwood strength classifications from C14 to C40 as well as a separate classification of hardwoods.

A guide to softwood grades with strength classes for timber from the UK, Europe and North America ~

BS EN 338: Structural softwood classifications and typical strength properties ~