Wood Grading Rules

Grading information

General Details

Oak Type: European Oak (Quercus Robus)
Oak Source: Central European
Plywood Type: WBP Birch Plywood
Plywood Source: Russia
Product Moisture Content: Between 8% – 11%
Length Specification: Minimum 80% between 1.8-2.8m, maximum 20% between 0.6 – 1.8m (unless otherwise stated)
Jointing system: Tongue & grooved all 4 edges
Edge profile: Bevelled 2 long edges only
Maximum Bow: Along the length – 30mm.  There can be some elements of tension between the 2 element of an engineered board which can create some bowing along the length this is perfectly normal.  The product is still suitable for installation if the bowing is within the allowed tolerance detailed within this section as correct fitment will ensure the boards sit flat when installed.

Thickness Options

20mm – Oak top layer 6mm (+/- 0.5mm) , Plywood 14mm (+/- 0.5mm)  – Overall thickness 20mm (+/- 0.3mm)
16mm – Oak top layer 4mm (+/- 0.5mm) , Plywood 12mm (+/- 0.5mm)  – Overall thickness 20mm (+/- 0.3mm)

Grade Options

Prime

Knot content: Only pin knots up to 5mm diameter allowed, limited to 3 knots per board.
Other defects: No bark pockets, splits or worm holes allowed.
Sap content: No edge sap allowed, limited core sap to 5% total volume.
Colour: Natural variation allowed, no dark heart wood allowed.

Nature 

Knot content: Healthy knots up to 20mm diameter allowed, filled cracked knots up to 20mm diameter allowed, filled dead knots holes up to 10mm diameter allowed.  Total number of knots limited to 3 per board.
Other defects: No bark pockets, splits or worm holes allowed.
Sap content: No edge sap allowed, limited core sap to 5% total volume.
Colour: Natural variation allowed, no dark heart wood allowed.

Rustic 

Knot content: Healthy knots up to 55mm diameter allowed, filled cracks knots up to 55mm diameter allowed.  Filled dead knots holes up to 20mm diameter allowed.  Total number of knots unlimited. 
Other defects: Limited small bark pockets allowed end splits up to 1mm in width and 100mm in length allowed, limited to 20% to total volume.  No worm hole allowed.
Sap content: Edge sap allowed limited to 30% of the width of the board.  Limited core sap to 15% of total volume.
Colour: Natural variation allowed, small amounts of dark heart wood allowed.