Quality classes
(on the basis of RT 21-10750-et)T – with full knots
O - gnarled
K - fir
M - pine
OV – knot-free
| Quality classes of weatherboards and floorboards |
||||
| Property | TK | OK | TM | OM |
| Cracks | Singel cracks, but not transversing crizzles, are allowed. In the ends the short transversing cracks, maximum board-wide, are allowed. |
singel cracks, but not transversing cizzles, are allowed. In the ends the short transversing cracks are allowed. | singel cracks, but not transversing cizzles are allowed. In the ends the short transversing cracks are allowed. | singel cracks, but not transversing cizzles, are allowed. In the ends the short transversing cracks are allowed. |
| Insect damages |
Not allowed. |
Not allowed. | Not allowed. | Not allowed. |
| Outer bark and beetle damages |
Not allowed. | Single small outer barks and beetle damages are allowed. | Single small outer barks and beetle damages are allowed. | Single small outer barks and beetle damages are allowed. |
| Rot | Not allowed. | Not allowed. | Not allowed. | Not allowed. |
| Spiral-grained annual ring |
Allowed to the extent it does not hinder the attachment of the board. | Allowed to the extent it does not hinder the attachment of the board. | Allowed to the extent it does not hinder the attachment of the board. | Allowed to the extent it does not hinder the attachment of the board. |
| Knot crackles |
Single, up to 8 mm knot crackles are allowed to the edges of usage side of the board. |
Single, up to 9 mm knot crackles are allowed to the edges of usage side of the board. | Single, up to 10 mm knot crackles are allowed to the edges of usage side of the board. | Single, up to 11 mm knot crackles are allowed to the edges of usage side of the board. |
| knot holes |
Not allowed. | Not allowed. | Not allowed. | Not allowed. |
| Knots | Complete knots with the maximum size of 1/3 of the width of the board and single per manent dry knots are allowed. |
Complete knots with the maximum size of 1/2 of the board are allowd. The knots should be permanent in most part. | Complete knots with the maximum size of 1/2 of the board are allowd. The knots should be permanent and with raw colour. |
Complete knots with the maximum size of 1/2 of the width of the board are allowed. the knots should be permanent and wholesome. |
| Paigad | Not allowed. | Not allowed. | Not allowed. | Not allowed. |
| Resin pockets | Small resin pockets are allowed to a small extent. The transversing resin pockets are not allowed. |
Small resin pockets are allowed to a small extent. The transversing resin pockets are not allowed. | Small resin pockets are allowed to a small extent. The transversing resin pockets are not allowed. | Small resin pockets are allowed to a small extent. The transversing resin pockets are not allowed. |
| Blue stain |
Not allowed. | Not allowed. | Not allowed. | Not allowed. |
| Finger joints |
Not allowed. | Not allowed. | Not allowed. | Not allowed. |
| Stripes of annaul ring |
The stripes of annual ring with the maximum lenght of half of the lenght of the board are allowed. | The stripes of annual ring with the maximum lenght of half of the lenght of the board are allowed. | The stripes of annual ring with the maximum lenght of half of the lenght of the board are allowed. | The stripes of annual ring with the maximum lenght of half of the lenght of the board are allowed. |
| Värvidefektid | Not allowed. | Not allowed. | Not allowed. | Not allowed. |
