Block Board Quality Standard |
Defects |
Unit |
Face |
Back |
|
|
BB/BB
Grade |
BB/CC
Grade |
BB/BB
Grade |
BB/CC
Grade |
Pin Knots |
Allowed |
Live knots |
Max. dia. (mm) |
19 |
25 |
19 |
30 |
Max. no. per m2 |
2 |
3 |
2 |
5 |
Half-Live knots; Dead Knots (no fall off); Inbarks Altogether |
Max. no. per m2 |
Not allowed
|
2 |
Not allowed
|
4 |
Half Live knots |
Max. dia. (mm) |
Not allowed
|
10 |
Not allowed
|
No limit |
Dead Knots
(no fall off) |
Max. dia. (mm) |
Not allowed
|
4 |
Not allowed
|
20 |
Inbarks |
Max. dia. (mm) |
Not allowed
|
15 |
Not allowed
|
20 |
Closed Splits |
Max. area (mm)
(% of total surface) |
Not allowed
|
Not allowed
|
Not allowed
|
2 x 300
permitted;
repaired
with similar
color putty |
Insect Holes |
Max. dia. (mm) |
Not allowed
|
2 |
Not allowed
|
Max. no. 4
Max. dia. 2 mm |
Max. no. per m2 |
4 |
No limit |
Face Contamination |
Max. area
(% of total surface) |
Not allowed
|
Not allowed
|
Not allowed
|
0.5 |
Discoloration |
Max. area
(% of total surface) |
Not allowed
|
5 |
Not allowed
|
40 |
Rot |
Max. area
(% of total surface) |
Not allowed
|
Veneer Shortage & Damage of Four Corners |
Not allowed
|
Not allowed
|
Not allowed
|
Not allowed
|
Delamination |
Not allowed
|
Blisters |
Not allowed |
Sand Through |
Not allowed |
Torn Grain |
Max. area
(% of total surface) |
Not allowed
|
Not allowed
|
Not allowed |
5 |
Excess Sanding |
Not allowed
|
Mending |
Max. size per surface |
Not allowed
|
Not allowed
|
Not allowed
|
≤ 50 x 100 mm
(boat shape) |
Max. no. per surface |
3 |
Core |
Uniform core strips
No insect holes or rot permitted
No gaps between core strips |
Core Mending |
Mended with wood-wool |
Panel Edge |
Smooth |
.gif){kind=spacer}