Larch wood with consistent colouring resulting from special heat treatment (without chemical additives). Larch plank in 3-layer construction with small bevel on long side and approx. 5 mm top layer, with approx. 5 mm backing in the same wood and middle layer conifer. Tongue and groove on all sides for easy installation. Heartwood with proportionate cracks is blended. Knotholes and cracks as well as pitch pockets are filled with black putty. Some sapwood is possible.