Infrared vs Traditional Saunas: What Is Finger-Jointed Wood Structures?

In addition to selecting high-quality materials, the stability and durability of the structural design are also crucial factors in building a premium infrared vs traditional sauna. As the functionality and practicality of sauna rooms continue to evolve, their assembly methods are also adapting to meet market demands. Th finger-jointed structure has gained significant attention and widespread application in the sauna industry due to its precision, efficiency, and seamless appearance.

Whether for achieving a natural wood texture through precise splicing or ensuring structural integrity and strength, the finger-jointed technique enhances the overall quality of sauna rooms. This article explores the finger-jointing process, its advantages, and its applications in modern sauna manufacturing.

What Is the Finger Joint Structure in a Sauna?

The finger joint structure, also known as a comb joint, is a commonly used wood joining method in sauna construction. The ends of the wood pieces are cut into interlocking sawtooth shapes and then bonded together with high-strength adhesive. This creates long, continuous boards with strong, seamless connections. Finger-jointed wood is widely used in both infrared and traditional saunas, especially for wall panels, ceilings, floors, and seating.

Infrared vs Traditional Sauna: Why Finger-Jointed Wood Works Well for Both

Whether it’s a modern infrared sauna or a traditional steam sauna, the finger-jointed wood structure has become an ideal solution for assembling sauna wood due to its excellent stability and efficient material utilization. Here’s why this structure is particularly suitable for sauna environments:

1. Excellent Resistance to High Temperatures and Humidity

Infrared and traditional sauna typically operate in high-temperature, high-humidity conditions, which can cause wood to warp, crack, or deform over time. The interlocking pattern of finger joints effectively disperses internal stress, enhancing dimensional stability. This means the wood remains intact and reliable even after prolonged exposure to sauna conditions.

2. Cost Efficiency and Material Optimization

Using full-length solid boards of premium woods such as Canadian red cedar, Canadian hemlock, or thermally modified hemlock is often costly. Finger-jointed wood allows smaller wood pieces to be joined into longer, usable boards, maximizing material usage and reducing waste. This helps maintain the performance and beauty of high-quality wood species while keeping costs under control.

3. Flexible Customization and Easy Installation

Thanks to the modular nature of finger-jointed boards, customers can easily customize sauna dimensions to meet their specific needs. These boards are produced in uniform sizes, making them easier and faster to install. The smooth joints also contribute to a cleaner, more seamless finish during assembly.

4. Enhanced Structural Stability

Finger-jointed boards are precisely cut and bonded using strong adhesives, eliminating common defects found in natural wood, such as knots and cracks. This creates a more uniform and durable material that can withstand the repeated thermal expansion and contraction associated with both infrared heating and steam environments, as well as exposure to anti-corrosive steam.

5. Aesthetic Appeal and Eco-Friendliness

Modern finger-jointed wood is manufactured with high precision, resulting in neat and nearly invisible seams. The surface is carefully sanded and treated for a refined, natural appearance, enhancing the overall beauty of the sauna interior. Additionally, by recycling smaller wood pieces, the process supports sustainable manufacturing and reduces environmental impact.

Where in the Sauna Room Do We Need to Use Finger-Jointed Structures?

When building a sauna room, material selection is a crucial step. Typically, there are two main construction methods for the sauna’s outer structure: one involves assembling full-length wooden boards one by one, while the other uses a spliced structure. For example, since Canadian red cedar is relatively expensive on the market, customers with limited budgets often opt for finger-jointed wood splicing instead of using whole solid wood boards.

As shown in the figure, finger-jointed wood is used between the wall panels and the ceiling in both infrared and traditional saunas. This structure increases wood utilization, extends the effective length of sauna wall panels, and helps customers save on material costs compared to whole solid boards. Additionally, since heat rises in a sauna, the ceiling experiences more frequent thermal expansion and contraction. The finger-jointed structure offers excellent deformation resistance at connection points, maintaining both the stability and the visual neatness of the wood.

Another key application is the sauna bench. When the customized bench length exceeds the standard wood length, finger-jointed splicing becomes a more economical and practical solution. It maintains the overall visual consistency of the bench while avoiding material waste and the high expense of using full-length lumber. This makes it an affordable and effective option for many customers.

Lastly, finger-jointed wood is also used in the sauna door and door leaf. Frequent opening and closing cause mechanical stress, and the door must also withstand heat. Finger-jointed wood is typically applied along the vertical edges of the door frame and within the door core. This enhances the durability of the entire door structure, reducing the chances of warping and cracking over time.

Infrared vs Traditional Sauna: Comparison of Different Structural Methods

There are three commonly used structural methods for building sauna rooms: finger-jointed structures, mortise and tenon structures, and tongue and groove structures. Each method has its own advantages and specific applications. The following is a comparative analysis for your reference:

Mortise and Tenon Structure

This traditional woodworking technique originated in China and has a history spanning thousands of years. It connects wooden components without the use of nails or glue, making it not only structurally sound but also a masterpiece of craftsmanship. While the mortise and tenon structure is incredibly strong and highly durable—even in high-temperature and high-humidity environments—it is complex to construct, labor-intensive, and cost-sensitive.

Because of its demanding craftsmanship, this structure is usually reserved for high-end, custom-built saunas or retro-style sauna projects. Compared to the finger-jointed wood structure, it offers greater structural stability and strength, but its high cost makes it unsuitable for most commercial and everyday residential applications.

Tongue and Groove Structure

The tongue and groove structure uses a protruding “tongue” on one board that fits into a corresponding “groove” on another. This design makes installation smoother, faster, and more secure. It provides excellent sealing and is ideal for assembling wall and ceiling panels in sauna rooms.

While not as complex as the mortise and tenon structure, and not as material-efficient as finger-jointed boards, it strikes a balance between ease of use and structural performance. Its moderate stability and high efficiency make it a popular choice in both residential and commercial settings.

Finger-Jointed Structure

Finger-jointed wood connects smaller pieces of wood into longer boards using interlocking cuts and high-strength glue. This method significantly improves wood utilization and is ideal for cost-efficient construction. It offers excellent stability in both infrared and traditional saunas, especially in environments with fluctuating temperatures and humidity levels.

Though some may associate finger-jointed wood with lower quality, it is actually a smart industrial solution—especially when the right supplier is chosen. This structure is widely used in walls, ceilings, benches, and even sauna doors due to its practicality, affordability, and overall performance.

Summary

Each structure serves a different market purpose and offers unique benefits:

Mortise and Tenon Structure: Ideal for those seeking premium visual appeal, traditional craftsmanship, and top-tier durability.

Tongue and Groove Structure: Best for projects that prioritize quick installation and a seamless finish.

Finger-Jointed Structure: The optimal choice for those looking for structural stability and cost-effective customization.

Is finger-jointed wood structure just a way to use up leftover materials?

Some customers may mistakenly believe that finger-jointed wood implies low quality or corner-cutting. While it’s true that some suppliers may compromise on quality, choosing a reputable manufacturer makes all the difference.

At Alphasauna, one of China’s leading sauna suppliers, we follow strict standards for material selection and production. We carefully select and splice only the best parts of premium wood through multiple rounds of inspection. Whether it’s sauna wall panels, benches, or other structural components, every board we use is free of dead knots, cracks, or visual blemishes. Our finger-jointed wood not only enhances product performance but also ensures a smooth, natural, and aesthetically pleasing finish.

Is the Glue Used in Finger-Jointed Wood Structures Environmentally Unfriendly?

Saunas operate in high-temperature and high-humidity environments, which raises concerns among many customers about the potential release of harmful substances from glue, especially in finger-jointed wood structures. However, there is no need for concern.

The glue used in finger-jointed structures is typically formaldehyde-free and certified by strict European environmental standards, ensuring it is safe and environmentally friendly even under sauna conditions.

Conclusion

As consumer demand for sauna customization continues to grow, traditional fixed-size sauna rooms are no longer sufficient. Finger-jointed structures have become a mainstream solution in the sauna industry thanks to their strength, stability, and economic efficiency.

They help reduce the cost of customized sauna rooms while delivering consistent quality and a better user experience. Alphasauna and its partners will continue to optimize structural systems and strive to deliver saunas with improved performance, higher durability, and greater design flexibility.

Summary

The above outlines the rigorous process Alphasauna follows to select and prepare premium wood materials—one of the key reasons why our prices may be higher than those of other suppliers using similar materials. We are committed to offering only safe, comfortable, and high-quality sauna rooms to both individual customers and B2B clients, ensuring they receive products with true long-term value.

If you are looking for fully customized sauna solutions, feel free to contact us. Based on your unique requirements, Alphasauna provides end-to-end service—from initial concept to final product—to bring your ideal sauna space to life.