If you prefer sauna wood stoves to heat your home sauna it's important to choose the proper rocks. Wood-burning heaters have a tray on top of the stove to hold a large quantity of igneous sauna rocks to produce steam and to increase the humidity inside the sauna. What many people don't know is the fact that not any rock will do. You have to be very selective when it comes to choosing the right type of rock.
The sauna rocks you choose for your wood stove must not contain any harmful minerals and they should have a large heat-storing capacity. Anything that contains sulphur ( as evidenced by the yellowish color of these types of rocks) should be avoided. Sulphur is not necessarily a health risk, but the smell of sulphur in the air is not exactly pleasant. Sedimentary rocks such as quartzite can literally explode when immersed in water. That leaves igneous stones as the best choice for home saunas.Igneous rocks contain minerals such as magnesium and iron. They are easily recognized by their dark color and they store the heat better than others. Volcanic rocks are also a good choice for wood-fired sauna stoves, if you can find them.
When it comes to size, pick igneous rocks of equal dimensions of about 3 to 4 inches in diameter. Stack the stones loosely on top of the sauna's wood stove in the shape of a small mound. Smooth stones found along rivers are good, too. Make sure you pick the ones found high above the high-water mark. Water-logged stones can burst when heated.
When you buy a wood stove for your sauna or a sauna room heater specifically built for home saunas, you have the choice of supplying your own or to get the igneous rocks that come with most stoves. The rock supply is usually included with the heater but 100 lbs. of stones will increase the shipping costs substantially.
