Oak Beam Grading Service

We have 2  BM Trada certified graders onsite, who can grade oak beams to the following specifications - THA , THB, TH1 & TH2 if requested, otherwise our standard grade is qp1 as below:

All our structural oak beams are visually graded to QP1 First grade specification at our French Sawmills

QP1 (first grade)

Sound knots are acceptable, as long as their diameter does not exceed one half of the width of the face or edge.

Some black bore holes can be accepted. Face shakes tolerated

Distortion

Tolerance of wane on two edges maximum if the minimum width exceeds 90% of the width of the piece.

Sapwood

Permitted as long as it is not exceeding half the width of the face or the edges is accepted on the edges.

THB / D30 (destructive grade)

The UK equivalent to QP1 grade, THB beams are individually visually graded and stamped onsite by an official TRADA registered grader to the following specification –

Sound Knots not greater than 0.75 of the thickness or width to which it relates.

Slope of grain not greater than 1 in 4.

Fissures

               Through the thickness - only permitted at ends no greater than the width of the pieces

                Not Through Thickness – Not greater than 1m or ¼ the length of the piece.

Distortion

                Bow – Not greater than 10mm over length 2m

                Spring – Not greater than 8mm over length of 2m

                Twist – Not greater than 1mm per 25mm width over length of 2m

                Cup – Unlimited

Bark Pockets

Permitted within 500mm of the ends, not greater than the width of the piece. Elsewhere not greater than 1.5 times the width or 0.2 times the length of the piece, whichever is the lesser

THA / D40 (destructive grade)

The UK equivalent to QPA grade, THA beams are individually visually graded and stamped onsite by an official TRADA registered grader to the following specification –

Sound Knots not greater than 0.2 of the thickness or width to which it relates.

Slope of grain not greater than 1 in 15. Within 500mm of ends not greater than 1 in 6.

Fissures

               Through the thickness - only permitted at ends no greater than the width of the pieces

                Not Through Thickness – Not greater than 1m or ¼ the length of the piece.

Distortion

                Bow –  Not greater than 10mm over length 2m

                Spring – Not greater than 8mm over length of 2m

                Twist – Not greater than 1mm per 25mm width over length of 2m

                Cup – Unlimited

Bark Pockets

Permitted within 500mm of the ends, not greater than the width of the piece. Elsewhere not greater than 1.5 times the width or 0.2 times the length of the piece, whichever is the lesser

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