Spruce tongue and groove board (Euro lining) is a profiled, planed board with a tongue-and-groove joint for wall and ceiling cladding. Profiles: Euro lining according to DIN 68-126/86 (with a shelf and an extended 8 mm tongue), Softline (without a shelf, creates a flat surface with rounded chamfers). On the back side - ventilation grooves for condensate drainage. Spruce (Picea abies) is valued for its light, uniform color from white to cream and low resin content - unlike pine, it does not release resin when heated, which is crucial for sauna and steam room cladding. Its porous structure provides thermal insulation properties higher than most conifers. A drawback is increased hygroscopicity. Dimensions: thickness 12.5 mm, working width 88 mm (with tongue - 96 mm), length 2000–6000 mm. Kiln-dried to 10–16% moisture. Grading: Extra class (knot-free), A (light live knots), B (dark knots up to 15 mm allowed), C (loose knots, resin pockets). Final processing is done on a four-sided planer. Installation - on clamps (hidden fasteners). GOST 8242-88. Production: Arkhangelsk, Vologda regions, Komi Republic - northern spruce wood with increased density. Packaging: shrink film, packs of 10 pieces. Applications: cladding walls and ceilings of living rooms, balconies, loggias, attics, saunas and steam rooms (spruce does not release resin when heated - safe for steam rooms). Block house and imitation timber are competing profiles for exterior finishing; Euro lining is preferable for interior work due to its small thickness (12.5 mm) and minimal reduction of usable space. Service life with proper treatment is 15–25 years. Protective and decorative coatings: oils (Osmo, Tikkurila), varnishes (acrylic, polyurethane), waxes. For saunas - specialized paraffin-based odorless compounds. Export documentation: phytosanitary certificate, certificate of origin. Shipment: containers, road transport.