Strong wood where are allowed healthy and repaired nodes and small cracks grouted. Resin pockets, color differences conditional age of the wood, cracks, nail holes, mechanical damages are permitted. The irregular holes from wormhole are a specific characteristic of this material. Gluing without defects. The long sides of the slats are not glued. Retro: Spruce aged C +, without any special requirements, cracks and knots stuccoed.