KVH quality
| Grading criterion | Requirements to be met by KVH® | Remarks | |
|---|---|---|---|
| Exposed areas (KVH®-Si) | Non-exposed areas (KVH®-NSi | ||
| Grading class compliant with DIN 4074-1 | Min. S10TS; C24 in accordance with DIN 1052 | The decisive strength and stiffness properties are given in DIN 1052. | |
| Moisture content | 15% ± 3% | The specified moisture content is a precondition for dispensing for the most part with preservative treatment and can also be the precondition for finger joint assembly. | |
| Type of cutting | Split-heart, free-of-heart on request | Split-heart | Split-heart: Given that the pith does not always automatically run through the middle of the log, split-heart is defined as follows: For a log with an ideal growth form, the pith would be cut through in two-strand cutting. Free-of-heart: Heart plank with d ≥ 40 mm is removed |
| Wane | Not permitted | Measured at an angle ≤ 10% of the smaller cross-section side | |
| Dimensional stability of the cross-section | DIN EN 336 Dimensional stability class 2:
w ≤ 100 mm: ± 1 mm w > 100 mm: ± 1,5 mm |
The dimensional stability for the longitudinal dimensions must be agreed between the customer and supplier. | |
| Knot condition | Loose knots and dead knots not permitted. Occasional faulty knots or parts of knots up to max. 20 mm in diameter are permitted | DIN 4074-1 Grading class S10 |
Replacement with natural wood dowels is permitted. Maximum of 2 adjacent to each other permitted for Si. |
| Knot diameter ratio | S 10: A ≤ 2/5 S 13: A ≤ 1/5 not exceeding 70 mm |
Knot diameter ratio A is determined in accordance with DIN 4074-1. The following applies for mechanical grading: - Knot sizes are not taken into consideration for KVH®-NSi - A ≤ 2/5 applies for KVH® -Si |
|
| Ingrown bark | Not permitted | DIN 4074-1 | |
| Cracks, radial cracks caused by shrinking (shrinkage shakes) | Width of the crack w must be ≤ 3% dof the respective cross-section width | DIN 4074-1 | For Si the requirements are higher than those applicable to grading class S10 in accordance with DIN 4074-1. |
| Pitch pockets | Width ≤ 5 mm | - | Additional criterion |
| Discoloration | Not permitted | DIN 4074-1 | For Si the requirements are higher than those applicable to grading class S10 in accordance with DIN 4074-1 |
| Insect attack | Not permitted | DIN 4074-1 | For Si the requirements are higher than those applicable to grading class S10 in accordance with DIN 4074-1 |
| Twisting | - | - | The permissible extent of twisting is not specified in further detail because no unacceptable twisting is to be expected if all the other criteria are complied with. |
| Longitudinal warping | for split-heart cutting ≤ 8 mm/2 m for heart-free cutting ≤ 4 mm/2 m |
for split-heart cutting ≤ 8 mm/2 m | In comparison: In accordance with DIN 4074-1 S10 und S13: ≤ 8 mm/2 m |
| Finishing of the ends | Trimmed perpendicular | ||
| Surface quality | Planed and chamfered | Leveled and chamfered | |
| Finger-jointing | DIN EN 385 | ||
You may be interested in: description KVH / sizes KVH