Choosing the right wood for a sauna is one of the most critical decisions you'll make in its construction. The type of timber you select affects everything from its durability and heat performance to its aesthetics and even the aroma of your sauna sessions. It's not just about what looks good; it's about selecting a material that can withstand constant cycles of high heat and humidity while remaining safe and comfortable to the touch.

At Finnmark Sauna, we believe in providing a wide range of premium, sustainably sourced timbers to meet every design preference and functional requirement. Our selection includes classic Nordic timbers, luxurious thermal modifications, and aromatic Western Red Cedar, all chosen for their specific qualities that make them ideal for the intense environment of a sauna.

In this comprehensive guide, we'll explore the essential characteristics that make a timber suitable for a sauna. We’ll then take an in-depth look at each of the woods we sell, helping you understand their unique properties and how they can contribute to your perfect sauna build.

The Essential Qualities of Sauna Timber

Before you choose your wood, it's crucial to understand the properties that distinguish a great sauna timber from a poor one.

• Low Heat Conduction: This is a non-negotiable. The timber used for benches, backrests, and interior cladding must remain cool enough to the touch, even when the sauna is at temperatures of 80–100°C. Softwoods are generally much better for this than hardwoods, which is why you'll rarely see timbers like oak or teak in a sauna.

• Durability and Stability: A sauna puts timber through a constant cycle of heating, cooling, and often, high humidity. The wood must be able to withstand these changes without warping, cracking, or shrinking. This dimensional stability is key to ensuring your sauna retains its structural integrity and airtightness over many years of use.

• Resistance to Moisture and Decay: High-humidity environments can lead to mould, mildew, and rot. The best timbers for a sauna have natural resistance to these issues, either due to their inherent properties or through a specialised treatment process. This ensures your sauna remains hygienic and looks great for years to come.

• Minimal Knots and Sap: Knots in wood are denser than the surrounding grain and can get incredibly hot, making them uncomfortable and even dangerous to touch. Additionally, the sap within these knots can melt and ooze out at high temperatures, creating a sticky mess and weakening the timber over time. For this reason, we primarily sell clear-grade or low-knot timbers, especially for areas like benches.

• Aroma: The aroma of the timber contributes significantly to the sensory experience of a sauna. Some woods, like Cedar, release a distinct, therapeutic scent when heated. Others, such as Aspen or Thermally Treated Alder, have a very subtle aroma or are nearly scent-free, which is ideal for people with allergies or those who prefer to add their own essential oils.

Our Range of Premium Sauna Timbers

At Finnmark Sauna, we have carefully selected a range of timbers that not only meet but also exceed the essential qualities required for a high-quality sauna.

Alder

Alder is a popular choice for benches and interior cladding due to its beautiful, smooth texture and lack of knots. It has a subtle grain pattern and a consistent light colour that creates a bright and airy atmosphere. Sustainably sourced from Finland and the Baltic regions, Alder is naturally durable, and its hypoallergenic properties make it a comfortable option for all users. It doesn’t release any resins or splinters, ensuring a safe and relaxing experience every time.

Aspen

Known for being completely hypoallergenic and resin-free, Aspen is an excellent choice for those with sensitive skin or allergies. Its light, clean appearance and smooth finish create a modern, minimalist aesthetic. Aspen remains cool to the touch even at high temperatures and has no detectable aroma, allowing you to enjoy a pure heat experience. It's a favoured material for benches and backrests due to its superior comfort and cleanliness.

Western Red Cedar

Our Western Red Cedar is a premium, clear-grade timber known for its natural beauty, durability, and rich aroma. This beautiful reddish-brown wood is naturally resistant to moisture, rot, and insects, making it a perfect choice for both traditional and infrared saunas. When heated, cedar releases a distinct, therapeutic scent that many consider to be the quintessential sauna fragrance. Its stunning colour and natural properties make it the perfect choice for a traditional, high-end sauna that will last a lifetime.

Thermally Treated Timbers: The Modern Sauna Standard

Our range of thermally modified timbers represents the pinnacle of sauna timber technology. The thermal modification process is a chemical-free treatment that heats the wood to very high temperatures in a controlled environment. This process fundamentally changes the wood's properties, making it significantly more durable, stable, and moisture-resistant than conventional timber.

Thermo Alder

Thermally treated Alder is an increasingly popular choice for contemporary sauna design. The process transforms its light colour into a warm, rich shade of brown. It retains the smooth, knot-free texture of natural Alder but gains enhanced durability and dimensional stability. This makes it an ideal choice for both cladding and benches where you want a modern, uniform look with the added benefit of superior performance.

Thermo Aspen

Much like Thermo Alder, thermally modified Aspen becomes incredibly stable and durable. The thermal treatment darkens the wood, giving it a beautiful, luxurious, deep brown tone. It retains its hypoallergenic and resin-free qualities, but with the added benefit of being much more resistant to moisture and warping. Thermo Aspen is perfect for creating a clean, modern aesthetic with a dark, rich colour palette.

Thermo Pine and Thermo Radiata

Thermo Pine and Thermo Radiata are excellent choices for cladding, offering a beautiful golden-brown colour and exceptional stability. The thermal treatment reduces the resin content in the wood, making it a cleaner and more durable material for sauna use. These timbers are perfect for creating a striking exterior or a warm interior that combines a classic feel with modern performance.

Thermo Spruce

Our Thermo Spruce is thermally modified from Nordic Spruce, a staple of Finnish sauna construction. The process removes the natural resins and darkens the wood, reducing its tendency to warp and making it highly resistant to moisture. Thermo Spruce is a great choice for both interior cladding and benches, offering a blend of traditional aesthetics and enhanced durability.

Other Exceptional Sauna Timbers

Hemlock

Hemlock is a durable softwood with a smooth, knot-free finish and a warm, consistent colour. It's a great choice for a refined, modern sauna interior, providing a sleek and clean aesthetic. Hemlock performs well in sauna environments, resisting warping and remaining comfortable to the touch.

Spruce

For a classic, authentic Finnish sauna feel, Spruce is the traditional choice. Our high-quality Grade AB spruce has a tight grain and low sap content, providing a cleaner finish than standard spruce. While it's a durable and affordable option, its natural knots mean we recommend it for cladding and framing rather than benches.

Decorative Juniper Panel

For a truly unique and aromatic accent, we offer decorative Juniper panels. These handmade panels, with their mosaic of juniper stems, provide a distinct aroma and create a beautiful, rustic feature wall. Juniper is known for its natural healing properties and fresh, forest scent, perfect for enhancing the ambience of your sauna.

Making Your Decision

Choosing the best wood for your sauna depends on a few key factors:

• Aesthetics: Do you prefer the rich, dark tones of thermally treated wood or the light, clean look of Aspen? Do you want the distinctive character of Canadian Cedar or the rustic charm of Spruce?

• Aroma: The natural aroma of the wood can significantly impact your sauna experience. Consider whether you prefer a strong scent like cedar, a subtle one from thermally modified wood, or no scent at all, such as with Aspen.

• Performance: For areas that will be exposed to the most heat and moisture, such as benches and floors, it's worth investing in a highly stable and durable timber like Thermo Aspen or Cedar.

• Budget: While we only sell premium timbers, there is a price variation between them. Spruce offers a more budget-friendly option without compromising on quality, while thermally treated woods and Cedar represent a higher investment for superior performance and aesthetics.

At Finnmark Sauna, we pride ourselves on providing not just the materials but also the expertise to help you build the sauna of your dreams. If you need any help choosing the right timber for your project, please don’t hesitate to get in touch with our experts. We're here to guide you through every step of the process.