Building a Sustainable Sauna: Best Material Choices

As more people become environmentally aware, building a sustainable sauna is now necessary. Today, manufacturers are designing saunas with eco-friendly materials that respect the planet and human health. But what are the best material choices for building a sustainable sauna? Read on to find out. 

Choosing Wood in Sauna Construction

Wood has been the standard sauna building material for centuries, offering insulation properties, natural aesthetics, and a soothing aroma. However, did you know that wood types are not created equal? This is true, especially regarding sustainability and performance under high-temperature conditions. Some of the wood you can choose to build your outdoor infrared sauna include:

·       Western Red Cedar

Western red cedar is famed for its natural resistance to decay, moisture, and insect damage, which comes in handy in a humid sauna. The wood’s thermal conductivity and low-density help prevent overheating, providing a comfortable experience even during high temperatures. The unique aroma of the western red cedar adds to the sensory experience, making the environment more inviting. If you opt for western red cedar, source it from sustainably managed forests to ensure it's eco-friendly. 

·       Thermowood

Thermowood is produced through a heat treatment process that enhances the wood's properties without using chemicals. The treatment increases the wood's resistance to moisture, pests, and decay, making it more durable. Thermowood's reduced moisture absorption capacity ensures stability in the changing humidity levels of a sauna. This prevents warping and prolongs the sauna’s lifespan. Thermowood is a great choice for sustainable saunas.

·       Hemlock and Nordic Spruce

Hemlock and Nordic Spruce are softwoods commonly used in woodworking and construction. Hemlock is mainly found in Asia and North America and comes with a light reddish-brown hue with a fine, straight grain. It is resistant to warping, strong, and durable, making it ideal for paneling and framing in saunas.

Nordic Spruce is native to Northern Europe and it features a pale yellowish-white hue with a smooth texture and straight grain. It is sturdy yet lightweight and is used in interior cladding. Hemlock and Nordic Spruce are both used in sustainable construction projects, thanks to their good mechanical properties and availability. 

Innovative Natural Materials

Innovative natural materials such as cob and hempcrete can be used to construct sustainable saunas due to their unique benefits. 

·       Cob

Cob is made from sand, clay, straw, and water. This mixture creates a breathable, strong, and thermally efficient building material. Cob’s high thermal mass allows it to absorb and slowly release heat and maintain consistent warmth with minimal energy use. These characteristics make it ideal for sustainable sauna construction.

Cob is non-toxic and free from synthetic chemicals, ensuring excellent indoor air quality. Sauna walls made from cob are thick and highly insulating. So, they help regulate humidity and prevent moisture buildup, reducing the risk of mold. The material is also fire-resistant, durable, and requires minimal maintenance.

·       Hempcrete

Hempcrete is a composite carbon-negative building material made from hemp hurds, lime, and water. It is a highly energy-efficient material that provides remarkable thermal insulation, lowering energy consumption for the best sauna for home. Hempcrete is breathable, which prevents moisture and mold buildup and improves indoor air quality without needing synthetic materials. It is worth noting that hempcrete does not require high-energy production processes, which reduces environmental impact.

Recycled and Reclaimed Materials

Using recycled and reclaimed materials when building the best infrared saunas gives your unit a unit design while helping reduce environmental impact. You can source reclaimed wood from industrial buildings or old barns to give your sauna a rustic charm. Use recycled metal for decorative accents and structural components to promote sustainability and contribute to a modern aesthetic.

Upcycling waste materials into building components is another innovative approach to sustainable sauna construction. For example, companies are changing waste such as plastic and rice husks into durable building materials. These materials can be used in different parts of the sauna, such as insulation and structural elements.

·       Insulation Materials

Proper insulation in sauna construction is crucial for maintaining the desired temperatures and improving energy efficiency. Choosing sustainable insulation materials ensures that the sauna is eco-friendly and cost-effective in the long run.

Natural materials like sheep’s wool, cork, and hemp are ideal for insulation due to their sustainability and high thermal performance. Sheep’s wool is moisture-regulating, breathable, and naturally resistant to mold. On the other hand, hemp and cork are non-toxic, renewable, and provide good thermal insulation. These materials prevent heat loss, reduce energy consumption, and maintain the sauna's temperature with minimal energy use.

Cellulose insulation, made from recycled paper products, is another sustainable material. It contains a high recycled content and requires less energy to produce. Cellulose insulation provides proper thermal performance and can be treated with non-toxic fire retardants, making it a safe choice for sauna construction. It also features soundproofing, high heat retention properties, and is free from harmful chemicals, ideal for enhanced indoor air quality.

Low-VOC Finishes

The finishes you choose for your sauna are as important as the structural materials. Sealants, coatings, and finishes applied to wood surfaces can impact indoor air quality. Many traditional finishes contain volatile organic compounds (VOCs), chemicals that quickly evaporate at room temperature and are released into the air.

When exposed to humidity and high heat, these chemicals can emit gas at a high rate, creating a harmful environment. Prolonged exposure to VOCs has been linked to respiratory issues, skin irritation, and headaches. Saunas are enclosed spaces where users breathe deeply in warm conditions. As a result, ensuring the air remains free from harmful substances is crucial for health and overall well-being. So, what finishes can you use when building a sustainable sauna?

·       Natural Oils and Waxes for Wood Protection

Natural oils such as linseed and waxes are among the most effective ways to protect sauna wood and maintain an eco-friendly, toxic-free environment. Linseed oil is extracted from flax seeds and can be used to seal wood. It improves the natural beauty of the wood grain and creates a breathable, water-resistant surface. Carnauba wax and beeswax can also be used to create a protective barrier on wood surfaces.

Natural waxes provide a soft sheen and prevent moisture absorption, making them ideal for maintaining the longevity of sauna interiors. Unlike synthetic finishes, which rely on chemical solvents, natural wood treatments come from plant-based sources and do not discharge harmful fumes. These finishes penetrate deeply into the wood, nourishing and protecting the wood against moisture, heat, and wear. 

·       Natural Stains and Pigments

Many sauna builders prefer a specific wood tone or finish to achieve a particular aesthetic. Instead of using synthetic stains that contain chemical dyes and VOCs, you can choose natural alternatives to achieve similar results without compromising air quality. Plant-based stains and mineral pigments provide beautiful coloration and have no toxic additives.

One simple and effective method of naturally staining wood is using household ingredients such as coffee, tea, or vinegar. These natural stains react with the tannins in the wood to create warm, rich tones without synthetic dyes. Iron acetate, made by soaking steel wool in vinegar, is another traditional method of darkening wood naturally. You can also mix clay and earth pigments with natural oils to create custom stains that enhance the beauty of the wood while remaining toxic-free. 

Finally

To build a sustainable sauna you must make conscious choices that prioritize energy efficiency, environmental responsibility, and health. Using responsibly sourced woods like cedar and hemlock ensures durability while protecting you and the environment from harmful treatments. On the other hand, natural insulation such as wool or hemp enhances breathability and heat retention, while low-VOC finishes maintain good indoor air quality. Choose the best materials today and construct a sustainable eco-friendly sauna and create a healthy space.