Cat. Selekt (according to PN-EN 13226: ○): Wood with a dark color throughout the entire cross-section.
Healthy pin knots with a diameter of up to 3 mm are allowed. White on the wear layer is unacceptable. Surface cracks are unacceptable, frontal cracks are hardly visible and do not penetrate. Slight color variation allowed. Natural grain.
Cat. Standard (according to PN-EN 13226: □): Wood with a dark color throughout the entire cross-section. Healthy knots and clusters of knots with a diameter of up to 10 mm are allowed, surface cracks with a depth of up to 1 mm. Shallow front cracks are allowed. Natural grain. Considerable color variety allowed. Properties not specified above in accordance with the Polish Standard No. PN-EN 13226:2009. Up to 3% of elements may have defects that do not meet the criteria of the declared class. In the case of slats with a finished or partially finished surface, edge runs are allowed in each class.
