Tongue and groove on all sides for easy installation. This particularly robust raw material originates from native mountain forests (Austria), from trees felled in the winter months.
Typical are bony, well-embedded knots up to 60 mm diameter and pronounced formation of the annual rings. Isolated knotholes up to 30 mm diameter are sealed with appropriate wood putty.
Two false knots per metre of plank length are permitted. Any flaws are corrected with other knots or matching patches. Stress cracks up to half the plank length are possible.
Variations in structure resulting from growth emphasize the old-wood character of the wood.