Although sawn timber can be purchased as "un-graded" or "run of mill" or "non-structural", it is generally sold as a graded product. There are several methods grading which predict the strength of the piece of timber and each of those methods is set out in an Australian Standard. Those methods include Visual stress grading, Machine proof stress grading and Mechanical stress grading. (See:
Sawn or Milled Timber).
F grades for sawn timber are provided by the visual stress grading system or by the machine stress grading system. (See: MSG).
F grades for round timber are provided by the visual stress grading system. (See: Round Timber )
The systems provide a set of grades with specific properties. The grades are F4, F5, F7, F8, F11, F14, F17, F22, F27 and F34.
|
