Tongue and Groove Board Brown – 120 x 18

Our Brown Tanalised Tongue & Groove (T&G) boards are among the sturdiest cladding options available. With a finished thickness of 20mm, they surpass standard 12mm and even 18mm boards in terms of sheer strength, durability, and insulation. Brown treatment is forced deep into the timber under pressure, providing long-lasting protection against rot and insects while giving the wood an immediate, attractive dark-wood aesthetic. The V-joint profile creates a clean, flush finish with a subtle decorative groove between each board. This design is highly versatile—lending itself perfectly to a rustic “log cabin” vibe or a sleek, contemporary vertical screen. Because of their significant 20mm thickness, these boards are the preferred material for constructing heavy-duty garden gates and security doors that need to resist warping and withstand heavy daily use. We stock these boards in a range of long lengths—1.95m, 2.1m and 3.9m—allowing for seamless installation on larger structures, reducing the need for joints and creating a more professional, weather-tight finish. Ultra-Heavy-Duty 20mm Profile: Provides maximum structural integrity and exceptional resistance to the elements. Rich Brown Finish: Pre-treated with a brown tint for a traditional look that eliminates the need for immediate staining. Modern V-Joint Aesthetic: Delivers a flush, interlocking finish that is perfect for high-end garden offices and workshops. Full Pressure Treatment: Tanalised (Brown) for long-term protection against wet rot, fungal decay, and wood-boring insects. Sustainably Sourced: High-quality softwood machined to a smooth, touch-safe finish.