How many stones should there be in a bathhouse?

After the long-awaited purchase of a sauna stove and its installation, the question arises: how many stones and what size should you put in?

Most stove manufacturers give their recommendations on installation methods and choice of stone type in their instruction manuals. In the characteristics of a heater stove there is always such a parameter as “Weight of laid stones”. But not everything is so simple: laying stone in a kiln has its own small nuances, which we will be happy to share with customers.

About the mass of laid stones

This characteristic for stoves is average because bath stones have different densities:

Type of stone for sauna stove	Density, g/cm³
Chromite	4,5-4,8

Therefore, the weight of the heater can accommodate almost one and a half to two times more stones.
However, if the oven is made of heat-resistant stainless steel, then it should not be overloaded. Although stainless steel has decent heat resistance, it becomes plastic at high temperatures, which, combined with significant overload of the heater, can lead to deformation of the firebox. Such a case will not be covered under warranty, and the oven will be damaged.
From a structural and aesthetic point of view, the stove should be filled with a slight heap or level with the top of the stone basket.
Using screens, economizers and stone baskets on the chimney
In order not to dry out the air, minimize hard infrared radiation and additionally accumulate heat in the stone, sandwich meshes are often installed on the first meter of the chimney. This solution has a positive effect on the microclimate in the steam room. Again, you need to remember that the entire load from the stones in the mesh, the weight of the chimney and the water tank (if any), is borne by the stove.
When choosing a fraction (stone size) for the mesh, you need to take into account that the chimney pipe will pass through it, which takes up a significant amount of space, and large stones may not fit. Most nets contain fine stones; usually in bath stores they are called “for electric heaters.”
The sequence of laying the stones is as follows: first fill the oven, then the mesh. In the process of filling the oven, you should immediately put aside small stones, which will then be used to fill the mesh.
Another tip for laying in a grid: fill it evenly on all sides and slowly move up. If you pay more attention to one side, then, most likely, the mesh will be slightly skewed, and it will be almost impossible to push stones through on the other side.

Boned or chipped?

The embanked stone is processed (boned) and has a smooth surface. Such stones look beautiful in a heater, but are always more expensive than crushed stones. There is an opinion that when embanked, the stone receives microcracks on the surface and therefore will last less than the chipped one. If you want exactly banked stones, then we can recommend filling the main part of the heater with crushed stones, and laying beautiful banked stones on the very top. When the stone becomes unusable, you will only update the top row.
Another feature of bunded stone: it has a smooth surface. When water hits a stone, it immediately bounces off and may not have time to warm up further, and if the stone is cold, then it simply flows down without stopping on the stones. When using crushed stones, the situation is better: the surface is rough, and water will stay on it longer. If the stove has cooled down a little, then when heated, the moisture will evaporate, and when it gets on the hot stones, the water will spend a little longer on them than on the banked stones and will produce more finely dispersed (light) steam. You don’t have to take stones so seriously; these questions usually bother people who are passionate about bathing, like us) But still, it’s better not to skimp on the stone, because it’s from the stone that we get steam, and not from the hot metal of the stove.

How many stones should I buy in the store?

• quartzite and crimson quartzite
• jasper
• quartz
• porphyrite

If you buy denser stones, then take more, for example, 1 box of 20 kg, since the stone is denser and 20 kg will have less weight in volume

Dense and therefore heavier stones:

• dunite
• jade
• soapstone (by the way, we do not recommend it)

It should be understood that in most cases, the denser the stone, the lower its porosity and the higher its specific heat capacity.

Thus, jadeite stores 2 times more heat than porphyrite.

Important advice before laying stones:

Before you start laying stones, you need to wash them, preferably two or three times.

Stones are usually covered with a layer of dust, especially diked ones. If you do not wash them, then over time all the small particles will end up on the floor in the steam room. The washed stone will show its true color and texture, and you will definitely be convinced that your efforts were not in vain.