Oak Beam Grading Rules - QPA and QP1
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Traditional Beams can supply structural oak beams in a variety of sizes. Please read below the oak beam grading rules for both QPA and QP1.
Appearance grade QPA
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- Sawn timber with sharp arrises; in case of pieces longer than 3 m, wane less than 10% of the face width is permitted across no more than 25% of the length.
- Sound sapwood permitted on two arrises if the total width is less than 15% of the face width.
Fully or partly intergrown sound knots are permitted if the diameter is less than one third of the face width.
- Dead knots, permitted where equivalent to two dead knots with a diameter less than 15 mm per linear metre.
- Boxed heart permitted, as well as slight traces of heartwood on two faces. Slope of the grain less than 7%, not exceeding 12% locally.
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Excluded: unsound knots, end shake, frost crack, ring shake, star shake, curly grain, bark pocket, unsound sapwood, brown pith, brown streak, rot, holes.
Appearance grade QP1
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- Sawn timber with practically sharp arrises, permitting wane less than 10% of the face width across no more than 30% of the length.
- This width tolerance is increased to 15% for sections above 250 x 250 mm.
- Sound sapwood permitted on two arrises if the total width is less than 15% of the face width.
- Fully or partly intergrown sound knots are permitted if the diameter is less than half the face width.
- Two dead knots are permitted per linear metre if less than one quarter of the face width.
- Boxed heart permitted, as well as traces of heartwood on both faces. Slope of the grain less than 12%, not exceeding 20% locally.
Permitted on a limited number of pieces: brown streak, black holes, brown pith.
Excluded: unsound knots, frost crack, ring shake, star shake, curly grain, bark pocket, unsound sapwood, rot, white holes.
Traditional Beams offer a number of fantastic structural oak beam solutions with nationwide delivery. If you require any further advise on oak beam grading please feel free to get in touch.