Why Thermowood is the Best Wood for Saunas

Building a Sauna and Wondering Which Wood to Choose? Thermowood Might Just Be Your Answer

This blog delves into why Thermowood is considered the best wood for saunas, highlighting its unique properties and benefits that make it stand out.

Introduction

Centuries ago, it was discovered that burning the surface of wood could extend the life of ship hulls and fortress posts. The practice of thermally modifying wood dates back to pre-Viking times, and it continues today. Now, we have a deeper understanding of the physical and chemical changes that occur in wood during heat treatment, which is the focus of this article.

You might have heard of thermally modified wood, also known as heat-treated or thermally treated wood. This differs from the more common pressure-treated wood. Pressure-treated wood involves using high pressure to infuse chemical preservatives deep into the lumber, extending its lifespan. This type of wood is commonly used for fence posts, decks, and other outdoor projects. While it's safe for use as the base of an outdoor sauna, it’s not recommended for interiors or other indoor projects due to the potential for low-level chemical leaching.

What is Thermowood?

Thermowood, also known as thermally modified wood, undergoes a special heat treatment process. This process alters the wood's cellular structure, enhancing its durability, stability, and resistance to decay and moisture. Essentially, it's wood that’s been toughened up to withstand extreme conditions, making it perfect for saunas.

What is the Process to Heat Treat Wood?

The exact process of heat treating wood varies by species and intended use, but the underlying principle remains consistent. Using a thermo-kiln, a heating chamber equipped with special sensors, the temperature is gradually raised to approximately 374°F (190°C) over two days. This process reduces the moisture content of the wood to 0%. Once this is achieved, the temperature is increased further to a specific level, followed by cooling and reintroducing moisture.

For outdoor products like saunas, more intensive heat treatment is required to enhance durability. In these cases, temperatures need to reach at least 419°F (215°C). However, while higher heat can improve durability, it's crucial not to overheat the wood, which can degrade its quality. The key is to apply just enough heat to enhance its properties.

While this process might seem straightforward—simply heat, remove oxygen, and re-add moisture—it is complicated by the need to maintain consistent quality across different batches. Variations in raw wood, influenced by factors like growth location, residual humidity, and temperature, present unique challenges. Therefore, the entire process must be carefully monitored to ensure uniform quality.

Benefits of Using Thermowood in Saunas

1. Heat Resistance One of the main reasons Thermowood is perfect for saunas is its exceptional heat resistance. During the thermal modification process, the wood is heated to high temperatures, making it capable of withstanding the intense heat inside a sauna without warping or cracking.

2. Durability and Stability Thermowood is incredibly durable. The thermal modification process increases the wood's density, making it more resistant to wear and tear. It also reduces the wood's moisture content, significantly lowering the risk of swelling, shrinking, or rotting.

3. Eco-Friendly Looking for an environmentally friendly option? Thermowood is your best bet. The thermal modification process doesn't involve any chemicals, making it a natural and sustainable choice. Plus, many types of Thermowood are sourced from sustainably managed forests.

4. Aesthetic Appeal Let’s not forget the visual aspect. Thermowood boasts a rich, deep color and smooth texture that enhances the overall look of any sauna. Its uniform appearance and beautiful grain patterns add a touch of elegance and luxury.

5. Low Maintenance Thermowood is easy to maintain. Thanks to its resistance to moisture and decay, it requires less frequent upkeep compared to other woods. A simple wipe-down is often enough to keep it looking pristine.

Why Choose Thermowood Over Other Woods?

There are several types of wood commonly used in saunas, including cedar, spruce, and aspen. While these woods each have their own benefits, Thermowood outperforms them in several key areas.

1. Heat Tolerance Unlike cedar or spruce, Thermowood can handle higher temperatures without deteriorating. This makes it particularly suitable for high-heat environments like saunas.

2. Dimensional Stability Other woods might expand or contract with changes in humidity and temperature. Thermowood, however, remains stable, ensuring your sauna structure remains intact and secure over time.

3. Sustainability While cedar and spruce can be sourced sustainably, the chemical-free treatment of Thermowood gives it an edge in eco-friendliness. It’s a greener choice for those looking to minimize their environmental impact.

Types of Thermowood We Sell

At Havenly, we offer a variety of Thermowood options, each suited for different preferences and needs:

• Thermo-Aspen Sauna Wood: Ideal for those seeking a medium light, fine-grained wood with excellent heat retention. Explore Thermo-Aspen Sauna Wood

• Thermo-Radiata Pine Sauna Wood: Known for its rich chocolate color and smooth texture, providing a luxurious sauna experience. Explore Thermo-Radiata Pine Sauna Wood

• Thermo-Spruce Sauna Wood: Offers a rustic knotty charm with high durability, perfect for traditional sauna designs. Explore Thermo-Spruce Sauna Wood

• Thermo-Alder Sauna Wood: Features a distinctive appearance and superior thermal properties, making it a premium choice. Explore Thermo-Alder Sauna Wood

Additionally, we offer sauna kits from SaunaLife, which utilize Thermowood for a complete and easy-to-install sauna solution. Explore SaunaLife Kits

How to Care for Thermowood in Your Sauna

1. Regular Cleaning Regular cleaning is essential to maintain the wood’s appearance and longevity. Simply use a damp cloth to wipe down the surfaces after each use. Avoid harsh chemicals that can damage the wood.

2. Ventilation Ensure your sauna is well-ventilated. Proper ventilation helps prevent moisture buildup, which can lead to mold growth and wood deterioration over time.

3. Protective Treatments While Thermowood is highly resistant to decay, applying a protective oil can enhance its lifespan and maintain its rich color. Choose oils specifically designed for use on thermally modified wood.

FAQs About Thermowood

• Is Thermowood safe for saunas? Absolutely. The thermal modification process is chemical-free, making Thermowood a safe and non-toxic option for sauna interiors.

• Can Thermowood be used for outdoor saunas? Yes, Thermowood's durability and resistance to moisture make it an excellent choice for both indoor and outdoor saunas.

• How does Thermowood compare in cost to other sauna woods? Thermowood can be slightly more expensive upfront, but its longevity and low maintenance costs make it a cost-effective choice in the long run.

Wrapping Up

Thermowood is, without a doubt, an excellent choice for sauna construction. Its unique combination of heat resistance, durability, and eco-friendliness makes it stand out from other woods. Whether you’re building a new sauna or renovating an existing one, consider Thermowood for a sauna that’s not only beautiful but built to last.

By choosing Thermowood, you’re investing in a high-quality, sustainable material that will provide a superior sauna experience for years to come.