Birch plywood grade
lease select defect or grade.
- Pin knot
- Knots: sound, intergrown, light and dark
Pin knot is a sound intergrown knot up to 3 mm in diameter.
The average of the minimum and the maximum diameters is taken as the knot (hole) diameter.
B
Allowable
Allowed: all grades, no size or amount restriction.
BB
Allowable
Allowed: all grades, no size or amount restriction.
C
Allowable
Allowed: all grades, no size or amount restriction.
CP
Allowable
Allowed: all grades, no size or amount restriction.
WG
Allowable
Allowed: all grades, no size or amount restriction.
The annual rings of an intergrown knot are intergrown with the surrounding wood over at least 3/4 of the knot’s cross-section perimeter.
Sound knot is one made of rot-free wood.
Light sound knot is one that is the same colour as the surrounding wood.
Dark sound knot is a sound knot that is much darker in colour than the surrounding wood, is extensively saturated with gum, tannin, and heartwood agents, and is frequently mottled.
The knot (hole) diameter is calculated as the average of the minimum and greatest sizes.
B
Allowable
Allowed: light up to 15 mm in diameter, with a shake up to 0.5 mm wide, 5 pc/m2.
BB
Allowable
Allowed: light and dark up to 25 mm in diameter, with a shake up to 1 mm wide, 10 pc/m2.
C
Allowable
Allowed: light and dark, no size or amount restriction.
CP
Allowable
Allowed: light and dark, no diameter restriction, with a shake up to 1 mm wide.
WG
Allowable
Allowed: light and dark, no size or amount restriction.
