Structural Grading for Oak
All residential and commercial property builds need Building Regulations approval, if structural Oak beams are used in the building they will need to be graded to BS5756 standards and CE certification issued to gain this approval.
BS5756 sets out the guidelines for visual grading of structural timber and the structural grades associated with each visual standard.
- THa and THb are the visual grades applied to larger section beams, over 20,000mm2 or 100mm thick
- TH1 and TH2 are the visual grades applied to smaller section beams, under 20,000mm2 or 100mm thick
The only structural grades that can be applied to Oak are D40, D30 and Fail. It does not matter that an individual piece of Oak may achieve a much higher grade, the highest it can be certified for is D40.
- THa and TH1 will achieve a D40 grade
- THb and TH2 will achieve a D30 grade
But remember, Oak must be wet graded, dry grading requires a maximum moisture content of 20%, which Oak over 150mm thick will never achieve.
Timberpride has a TRADA trained grader who can inspect and issue CE declaration of performance certification with your order. One less thing to worry about. Please call us on 01666 504 436 for more information.