The sauna is a place where we can relax and renew our strength while taking care of our health. Choosing the right material to finish the interior of the sauna is crucial to ensure the comfort of use and the durability of the structure. One of the most commonly chosen wood species for sauna finishes is Linden.
Linden is chosen for its unique properties – it is lightweight, insulates heat well and at the same time is resistant to changes in humidity, which is crucial in a sauna environment. In addition, Linden is hypoallergenic and emits a pleasant, relaxing aroma when exposed to heat.
Benefits of using Linden in the sauna
Linden is an excellent choice for finishing the interior of a sauna due to the many benefits it offers.
- Durability and longevity: lime is known for its exceptional durability. With proper protection and maintenance, elements made of lime can last up to 100 years. Lime stands up well to the rapid changes in temperature and humidity that are inevitable in a sauna, without cracking or deforming.
- Hypoallergenic properties: linden is a tree species with a low allergen content. This is particularly important in the sauna, where the skin comes into direct contact with the surface of the tree. Lime also emits a pleasant, subtle aroma that has a relaxing effect on the nervous system.
- Moisture regulation: Lime has the ability to naturally regulate moisture due to its porous structure. This allows the sauna to maintain an optimal humidity level, which translates into comfort.
- Lightweight: Lime is a relatively lightweight tree species, which makes the sauna easier to construct and reduces the load on the foundation. This is especially important for larger constructions where the weight of the material can be a problem.
- Comfortable to the touch: The surface of the lime tree is smooth and pleasant to the touch, which provides additional comfort when using the sauna.
- Safety: Lime does not heat up to high temperatures, which minimises the risk of burns on accidental contact.
- Aesthetics: Lime has a nice, light colour that can vary from white to honey. This variety of tones makes lime an aesthetically appealing material. Compared to aspen boards, lime boards do not leave yellow stains from human sweat.
Choosing linden as a sauna finishing material is a decision that will bring many benefits in terms of both functionality and aesthetics.
Potential challenges when using linden in a sauna
Despite the many advantages of linden as a sauna material, there are a few potential problems, but these can be effectively minimised with proper maintenance and care.
- Mold susceptibility: Linden wood can be susceptible to mold and fungi, especially in conditions of high humidity. However, if the humidity in the sauna does not exceed 60%, proper ventilation and regular drying of the room are sufficient to maintain the wood in good condition. There are practically no issues with linden wood when used in the construction of a Finnish sauna, where the air humidity does not exceed 20%. In the case of using linden wood in wet sauna conditions, thorough drying and ventilation of the room after use are necessary.
- Darkening over time: Linden wood tends to darken over time, which can affect the sauna’s aesthetics. However, regular treatment of the wood with special waxes or oils can help maintain its light, natural appearance. Additionally, for some people, this is not considered a drawback. The natural darkening of the wood adds a certain charm to the sauna.
- Need for regular maintenance: Linden wood requires regular maintenance to preserve its properties. This includes cleaning, protection against pests, and the use of appropriate wood maintenance products.
In summary, despite potential challenges, with proper maintenance and regular upkeep, linden wood is an excellent material for sauna construction. By properly treating the wood before sauna construction and implementing regular maintenance, it is possible to effectively manage and minimize these issues.
Building a Linden Wood Sauna
Let’s talk about finishing the sauna walls with linden wood paneling. The most common type of linden wood profile is STP, which guarantees efficient use of the material due to its optimal thickness and width. Available in various lengths, it allows for precise fitting to the building’s structure. The paneling is installed on a specially constructed wooden frame made of directional blocks with a cross-section of 50×50 mm or 40×50 mm.
The cells of the frame are filled with insulation material, on which a sauna-grade aluminum foil with a thickness of at least 100 microns is placed. The paneling is attached to the beams using special clips that allow for easy removal of the profile without damaging it.
When it comes to sauna benches, linden wood is an excellent choice. It offers a smooth, pleasant surface that does not heat up to the point of causing burns. The hypoallergenic properties of linden wood, as well as the actual phytoncides it releases under the influence of steam, provide additional health benefits.
The bench frame can be made of pine blocks with a cross-section of 50×70 mm. The construction consists of 3-5 supports and crossbars. The bench planks are attached to the frame from the inside using screws to prevent metal nuts from burning individuals during sauna heating.
Characteristics of linden wood compared to other types of wood
| Wood | Density kg/m3, at 15% moisture content | Resistance to decay and insects | Water resistance | Color | Resin content | Thermal conductivity, mWt/m3, across fibers/along fibers |
| Linden | 500 | Low | No | Light yellow or honey | No | 150/150 |
| Alder | 530 | Low | No | From light brown to medium brown | No | 200/200 |
| Oak | 700 | High | Yes | Rich brown color, ranging from light to dark shades | No | 200/400 |
| Aspen | 500 | Low | No | Typically light beige color, almost white | No | 190/190 |
| Pine | 510 | High | Yes | From light brown to medium brown with a reddish hue | Yes | 200/400 |
| Larch | 670 | High | Yes | Red-brown color that darkens and becomes more saturated over time | Yes | 130/130 |
How to distinguish linden wood from aspen
Differentiating between wood species can be challenging for the average person. Linden wood is often mistaken for aspen. Both tree varieties are considered ideal for saunas, but they differ significantly in terms of cost – linden wood is more expensive than aspen.
The primary criterion for distinguishing linden wood from aspen is the color. Unlike linden wood, which can have various shades from white to tan, aspen is characterized by a white, almost snowy appearance.
Another important criterion is the scent. Linden wood has a distinctive sweet, honey-like fragrance, while aspen has a bitter aroma reminiscent of birch sap. After processing, the surface of linden wood becomes silky, whereas some roughness can be felt on aspen. Dark, protruding knots are also commonly found on the surface of aspen.
Properly processed linden wood can serve in the sauna for up to 100 years. It is important to coat the finishing material with various protective agents to shield it from environmental factors, pests, and for decorative purposes as well.
