TESLI EXTRA MIX Thermo Basswood Tongue & Groove Sauna Board | Lumber – Premium Cladding for Saunas and Interior Wall Finishes

The TESLI EXTRA MIX Thermo Basswood Sauna Board | Lumber is a high-end tongue & groove cladding material designed for use in saunas, steam rooms, relaxation zones, balconies, and interior paneling. Made from thermally modified basswood, it offers a combination of elegant appearance, moisture resistance, and long-lasting performance—ideal for high-humidity environments.

This EXTRA grade sauna board is meticulously hand-selected for a clean, nearly knot-free finish. The smooth tongue & groove profile allows for easy installation and a seamless, modern look, while the natural thermal treatment results in a beautiful caramel hue and enhanced durability.

Key Features:

• Premium Thermo Basswood: Heat-treated for improved moisture resistance, dimensional stability, and a rich caramel tone
• Precise Dimensions: Working width: 70 mm (2 3/4″), thickness: 12 mm (1/2″), lengths: 1,900–3,000 mm (6’3″–9’10”)
• Tongue & Groove Fit: Offers secure installation and a smooth, continuous wall finish
• Comfort and Safety: Low-density basswood stays cool to the touch—ideal for hot environments like saunas
• Natural Aroma: Releases a soft, honey-like scent that enhances the spa experience
• EXTRA Grade Quality: Nearly knot-free, sap-free, hand-selected boards for a clean, high-end appearance
• Custom Finish Option: Can be treated with linseed oil for a deeper tone and added protection

The TESLI EXTRA MIX thermo-treated sauna board is perfect for DIY sauna kits, custom spas, and elegant interior upgrades. Now available for sale in the United States and Canada. Not sure how much you need? Use our DIY sauna kit calculator to plan your project.