The right sauna stones not only keep the heat longer and decorate the interior of the steam room, but also enhance the therapeutic effects of steam. Therefore, most sauna professionals recommend giving preference to natural stones, which retain their natural structure and energy. However, stones made of different materials have different properties. In this article we will try to understand the similarities and differences in minerals that are suitable as sauna stones.
- What parameters to pay attention to when choosing stones for the sauna
- How to take care of the stones in the sauna
- How to properly arrange the stones in the sauna heater
- Should you buy sauna stones, or should you find your own by the river or in the woods?
- Best sauna stones
- Olivin diabase
- Crimson quartzite
- White quartz
- Basalt or volcanite
- Cast iron, porcelain and ceramic sauna stones
- Turbo Coils – Stainless Steel Furnace Heating Shafts
What parameters to pay attention to when choosing stones for the sauna
Density. It is believed that the higher the density of the stone, the better.
Heat capacity. This is the ability of a stone to store and retain heat fast enough when it is heated that it can then slowly release it to the environment when it is cooled. Heat capacity is measured by the amount of heat a body can absorb per unit mass. When choosing stones for your stove, you can find and compare these values for different rocks.
Heat resistance. This is the ability of stones to withstand sudden changes in temperature for an extended period of time. There is a simple test that allows you to determine the quality of stones according to this characteristic, but it requires the right conditions, so it cannot be done before buying stones. However, it is possible to sift out the worst quality stones this way. Stones should be heated to the maximum, and then immersed in cold water. Suitable unsuitable stones should be those that are cracked or porous.
Ecological. If you are collecting stones yourself, choose an environmentally friendly area, away from landfills, railroad tracks and industrial zones.
If you buy stones in a shop, ask the shop for a certificate of conformity. This is also important because unscrupulous vendors instead of one breed of stone may sell you another cheaper one, so be careful and do some preliminary research with photos and videos of the mineral you like.
Uniformity of structure. First, it is about the absence of inclusions of other rocks in the main mineral: they may have different thermal resistance, which means that such stones will be more susceptible to damage. Second, it is important that the surface of the stone is relatively smooth and without cracks. If you inspect each stone meticulously, you can also tap them against each other to reveal hidden pits, if they exist.
Uniformity of size and form. This is also an important feature that ultimately affects all other indicators. If the stones are of equal size and shape, the air in the sauna will be heated evenly, and the air and steam will circulate in a harmonious manner. Round or oval stones with a smooth surface about the size of a fist or slightly smaller are considered optimal. Although there is an opinion that chopped stones have a larger surface area and therefore give off more heat, round stones will serve longer because they are less prone to cracking.
There are no carbonates on the surface of the stones. They are white spots that look like plaque. They are easily scraped off with sharp objects, which means they will just as easily become airborne as dust when the stones are exposed to heat and moisture.
How to take care of the stones in the sauna
Over time, natural stones deteriorate. As a result, sauna stoves lose 15% to 30% of their heat output per year, depending on how often they are used. Therefore, it is important to replace the stones in a timely manner and perform quality control. It is recommended that the stones in the sauna stove be thoroughly inspected and replaced at least once or twice a year, and completely replaced every two years.
During the inspection, the stones should be removed from the sauna stove, rinsed with running water and rechecked for chips and cracks. Stones that have begun to crumble should also be replaced, as the dust from them easily enters the air and can be harmful to the lungs.
There are several calculations to determine how many stones are needed for a given sauna stove. You can assume 5-6 kg of stones per m2 of steam room, or calculate 1 part of the volume of stones per 50 parts of the volume of the steam room. Of course, the characteristics of the sauna stove should also be taken into account. Incidentally, in an open heated sauna stove, where the heating temperature of the stones is much lower than in a closed stove, you can use less heat-resistant stones and they are cheaper.
How to properly arrange the stones in the sauna heater
Before adding the stones to the sauna heater, it is recommended to inspect them thoroughly, preheat and cool them, remove stones that are faulty and soak them in a weak salt solution for several hours. Then start placing the dried stones in the sauna oven. If the stones are not homogeneous enough, we recommend placing the larger stones in the bottom rows and the smaller ones on top.
If the sauna stove is metal and small, use smaller stones. Smaller stones are better suited for electric stoves, as they can be easily placed between the heating elements. Larger stones are better suited for larger wood-burning stoves. So check the model and function of your sauna stove.
Stones that are too large in a metal sauna stove can cause water to get on the metal due to the large gaps between the stones, resulting in unpleasant, hard steam, which is why it is important to evenly distribute stones of the right size inside the sauna stove.
Should you buy sauna stones, or should you find your own by the river or in the woods?
This often depends not only on financial possibilities, but also on tastes. For example, jade cannot be collected on your own, even if you really want to. But river gravel or sea pebbles can be quite accessible, and such a trip will bring a lot of positive excitement. But of course, it is also a matter of time.
If you decide to collect stones for bathing with your own hands, take care to choose the right place to be sure of the purity of the collected stones. It is advisable to evaluate them not only for chemicals or other contaminants, but also for radiation background, because stones accumulate radiation and even if the radiation background around them is relatively safe, it is worthwhile to additionally check the stones. So it is better to carry a suitable dosimeter to measure radiation levels.
You can check the stones for chemical compounds by heating them: heating them can cause an unusual smell.
If you buy ready-made stones, you additionally have a choice of different rocks. In addition, you don’t have to worry about the safety of the materials.
Best sauna stones
If we compare different types of stones for the sauna stove according to important criteria, the following apply:
- The most durable: ceramic, jade, peridotite.
- The most demanding in terms of heat: porphyrites.
- Most dense: jadeite, nephrite, peridotite.
- Cheapest: gabbro-diabase
This stone is rightly at the top of the ranking of sauna stones. It has only one disadvantage, but a significant one: being a semi-precious stone, it is very expensive. However, many people are not embarrassed by its obvious advantages:
- High heat capacity. Jadeite has a very dense structure and gives off heat for a long time.
- It does not form cracks, expanding and contracting evenly with temperature changes.
- Its therapeutic effects include ionization of the air, saturation of water with metaceramic acid, disinfecting effect, alignment of human energy field (according to bioenergetics). Jade is considered particularly useful for joint diseases or predisposition to them.
- Attractive appearance. The stone has a deep green color, pleasant to the eye and suitable for almost any interior.
Given that jade is an expensive mineral, it can be used in combination with other stones, for example, covering the top layer of a sauna stove with jade. Jadeite has a lifespan of no more than 5 years, after which it completely loses its properties and needs to be replaced.
This stone also belongs to the category of semi-precious minerals and is similar to jade in its basic properties. Normal nephrite also has a green tint, but this depends on the additives used. You can also encounter pink, brown and even black nephrite.
Nephrite has wide-ranging effects on the body, and in Oriental countries it is considered a cure for all ailments. What can be said for sure is that nephrite has an overall revitalizing effect.
It is important not to confuse nephrite with the cheaper stone serpentinite, so be careful when buying it. Serpentine is much less durable and does not have the same healing effect.
One type of stone that is popular in Poland is diabase olivine stones. These stones are characterized by their ability to withstand high temperatures and are ideal for use in a sauna.
Olivine diabase is a volcanic stone that comes in a variety of colors, from dark green to black. Its main advantage is that it heats up slowly, but keeps warm for a long time. Therefore, when it is used in a sauna, you can get a long-lasting effect, which is especially desirable in a Finnish sauna, where the temperature can reach up to 100 degrees Celsius.
One disadvantage of diabase olivine stones is their price. They tend to be more expensive than other sauna stones, such as basalt or granite. However, their durability and longevity make them worth considering purchasing. In addition, these stones have a positive effect on health, as they give off special minerals that benefit the body. Therefore, if you are planning to choose stones for your sauna, olivin diabase is a great choice.
Longtime sauna fans call it the “king of saunas.” Talcochlorite has a high heat capacity, it heats up very quickly, and the heat waves that emanate from it as it cools down are close to the natural radiation of the human body.
The stone has a pleasant gray color (it comes in various shades of gray), gives very soft comfortable heat, emits healthy substances in high concentration and serves for a long time. Its only disadvantage is its high price.
It is a rock of volcanic origin, the core of which is silica. Porphyritis is popular as a sauna stone because of its good heat capacity, but being a heterogeneous structure it is quite prone to cracking. However, it usually lasts for several years.
Before buying porphyrites, its sulfide content should be evaluated. This can be done by a cursory examination of the surface of the stones. Sulfides look like grayish streaks with a metallic sheen. They can look like golden specks. A small amount of them in a stone is quite acceptable, but if they occur frequently and occupy more than 5% of the stone’s surface, it is better to hold off on buying stones. Stones with a high content of sulfides when heated can have an unpleasant odor and cause farting or burning in the throat and eyes.
Properly selected porphyrites generally do their job well, but public saunamasters who have the opportunity to compare steam from different sauna stones do not speak in favor of porphyrites. Porphyrites are popular, however, because of their affordability. And the unpleasant “sulfuric” smell usually disappears completely after a few heating cycles.
Gabro-diabase is also of volcanic origin, but is stronger than porphyrites. It even resembles talcochlorite in its properties, but is much cheaper and thus more popular.
Gabro-diabase is especially recommended for people with respiratory problems, asthmatics and anyone prone to frequent colds.
The disadvantages of this mineral are the possibility of an unpleasant odor, significant expansion when heated (this must be taken into account when placing the stones in the sauna stove) and a tendency to crack.
Otherwise known as porphyry. It has a pleasant brown or maroon color, a solid, homogeneous structure and a high heat capacity. In addition, this stone creates an excellent therapeutic effect: it normalizes blood pressure and improves the tension of blood vessels, reduces joint pain, reduces meteorological dependence, has a beneficial effect on the genitourinary system.
Steam from raspberry quartzite is very light, the stone is durable in use, and it retains its external attractiveness and healing properties for a long time. The disadvantage, as you have probably already guessed, is also the price. In addition, due to its high density, it is difficult to process, so you will not find porphyry stones for bathtubs in round or oval shapes, but only chopped ones.
It is a very beautiful white mineral, sometimes translucent. It is also called “hot ice” because it creates a cold glow effect when heated. In general, this mineral looks very beautiful and perfectly complements any interior.
An important feature of white quartz is the release of ozone at high temperatures, which has a rejuvenating effect. Also, the steam from white quartz promotes breath cleansing and is suitable for people with frequent colds.
However, it cannot be called permanent, so it is recommended to check white quartz stones frequently (every 6-8 months) for cracks. In addition, this mineral in the right quantities for the sauna is quite expensive.
It is a magma mineral that is similar to jade in its properties, but is much cheaper due to its higher silica content. It has high heat resistance and the same healing properties, although to a lesser degree. It has a disinfectant effect, helps with joint disease, and ionizes the air.
Basalt or volcanite
Basalt is basically solidified lava. Basalt is excellent as a sauna stone due to its high density, resistance to heat and ability to withstand numerous temperature fluctuations.
In addition, it has a positive effect on the nervous system, normalizes metabolism and improves thyroid function.
This stone is also an igneous rock and is very suitable for our purposes. It is resistant to cracking, almost does not expand when exposed to heat, and has a lifespan of about 5 years.
It is often used in saunas in the Urals, where it is called “black sauna stone.”
Chromite is also good for people prone to colds and improves the functioning of the reproductive system.
It is not the most common variant of bath stone, but with excellent properties, both technical and medicinal. This semi-precious stone comes in various shades, often dominated by brown or red. It is very resistant to high temperatures.
Jasper steam helps with headaches, insomnia, diseases of the reproductive system, depression, has a beneficial effect on the nervous system.
A very striking stone with a white or gray hue, it is very popular as a banyan stone in Russia. Being relatively inexpensive, it nevertheless performs necessary functions well. In addition, calcite has pronounced medicinal properties and helps with genitourinary diseases and colds.
Cast iron, porcelain and ceramic sauna stones
Of course, they are not stones as such, but are called so because of their function.
The main advantage of cast iron stones is their durability. And if you compare with natural stones, the thermal conductivity of cast iron grains is about 30 times higher. Steam from cast iron is very hot and dry, so experts recommend using cast iron cores along with stones.
It is a convenient inexpensive option that has the highest performance in all technical categories. The only disadvantage they have, in fact, is their unnaturalness and energetic coldness. That’s why lovers of natural materials still prefer stones.
Porcelain balls fall into the same category of unnatural stones. They are an inexpensive, durable filling that is also aesthetically pleasing. So-called porcelain stones are made of aluminum oxide and clay. They are heat-resistant, durable and last a long time. And if you mix porcelain stone with natural stone when laying a sauna stove, you will enhance its therapeutic effect.
Ceramic balls are made of white clay, quartz, feldspar and animal bones. All organic components are burned and evaporated during the creation of such balls. Such balls reach the end user completely safe.
As a rule, cast iron, porcelain and ceramic stones are used in furnaces with a closed sauna heater.
Turbo Coils – Stainless Steel Furnace Heating Shafts
Turbo coils are a novelty and are unknown to the Polish consumer. The stainless steel coils are designed to increase the efficiency of closed type sauna heaters as an alternative to traditional sauna stones.
The design is a sealed coil pressed into the housing. This allows water to penetrate inside and thus not only the surface of the coil, but also the entire coil inside works in evaporation.
The coil is made of austenitic-grade stainless steel, which is virtually free of corrosion and will not deteriorate or dust when exposed to water.
The weight of a stack of coils in a closed sauna oven is 2-2.5 times that of a stone stack.
By placing the coils tightly on the flat bottom of the sauna stove, water is kept to a minimum, which prevents a sudden drop in temperature in the sauna stove and prolongs its life.
Sauna coils are cylindrical and can be installed in both flat-bottom and horizontal cylindrical sauna stoves.
Advantages of using coils:
- Reduce by half the time it takes for the sauna heater to be ready;
- water evaporates efficiently;
- the life of the sauna stove is extended;
- environmentally friendly, dust-free, non-crumbling;
- long service life;
- have a universal geometric shape.