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How to Choose Sauna Rocks

You can’t have a good sauna experience without the right sauna rocks. In this article, we’ll help you choose the perfect rocks for your sauna.

Choosing the Sauna Rocks

To choose the best rocks for your sauna, you need to consider:

  • The type of rocks
  • The size of the rocks
  • How safe they are to use

Let’s take a deep dive into each option.

1. Type of Rock

Rock researchers group rocks into 3 types – igneous, sedimentary, and metamorphic. Igneous is most suitable for a sauna. It is made from cooled magma and lava. And it’s the oldest rock on Earth. 

Examples of igneous rocks are Basalt, Granite, Gabro, Peridotite, Olivine, Vulcanite, etc. 

different types of igneous rocks
Different types of igneous rocks (source)

That said, not all igneous rocks are suitable for the sauna. For instance, Pumice and Obsidian are not dense enough to hold heat. So make sure you pick the non-porous, dense ones. 

You can carry out a small experiment to determine if a rock is dense enough. Use a hammer or drop the rock on a hard floor. If it breaks or chips away then the rock isn’t dense enough. It could explode when you start heating it (more on this later).

2. Size of Rock

It’s a good idea to get a variety of sizes – small, medium and large. You can place the large ones at the bottom and the medium ones at the top. Small rocks can be used to fill in gaps. But if finding a variety of rocks is difficult, then just get medium-sized rocks. 

Make sure you don’t spread the rocks too sparsely. The water will run down without soaking the rocks. But also don’t arrange them too tightly. You would still have a hard time soaking the rocks. 

3. Safety Issues 

Not all rocks are suitable for a sauna. Using the wrong type of rock can lead to an explosion. So while you can collect sauna rocks from your garden and public parks, be very careful. To make sure that the rocks can withstand heat, here are a few tests you can perform:

  • Scratch it with your nails. A good rock will not chip away. 
  • Drop it on a hard floor. A good rock will not break. 
  • Throw it into the fire, heat it thoroughly and then plunge it into cold water. A good rock will not crack.

Best Sauna Stones

Looking for the best stones for your sauna? Look no further! Check out our review of the best sauna stones here.

How To Prepare Sauna Rocks For First Use

To prepare sauna rocks for first use, you need to follow two major steps. Those are:

Step 1: The rocks must be soaked and thoroughly rinsed to remove the stains and dust. Continue with the process until the water starts to look clear. 

Step 2: Place the rocks inside the heater. Lay the heavy ones at the bottom and pile the medium ones on top. Small rocks can be used to fill in gaps but make sure the rocks are not too tightly packed. Place the stones to support the heating elements and do not bend the elements. 

It’ll be hard to get it right the first time. Don’t worry. Just reposition the rocks. 


Q. How to heat sauna rocks?

A. You can heat sauna rocks by using a sauna heater or stove. There are two types of heater – electric and wood. Place the sauna rocks over the heater and switch the heater on. Then, splash some water over the rocks to produce heat.

Q. What is so special about sauna rocks?

A. Sauna rocks are special because they absorb and retain heat. When you heat sauna rocks using wood or an electric heater, it holds the heat and keeps the room warm. 

Q. Do you need to replace sauna rocks?

A. Yes, you need to replace sauna rocks. But you don’t need to do it after every sauna session. If you are a regular sauna user, replace the rocks every 4 – 6 months. Non-regular sauna users can replace the rocks once a year. 

Q. Are lava rocks good for a sauna?

A. Yes, lava rocks are good for sauna. They are great heat absorbents and very durable.

Final Thoughts

That’s it, folks. We hope you enjoy your new sauna rocks and have a great sauna session. If you have any questions, leave a comment below.

Feature image by Oliver Paaske on Unsplash

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