Harvia Olivine Diabase Traditional Finnish Sauna Heater Stones (5-10 cm, 20 kg)

Olivine diabase sauna heater stones are the recommended sauna stones for all heater types and is a subvolcanic rock mined in Western Finland. This traditional stone type is durable in structure and thanks to its high density, it stores and releases heat well. This guarantees perfect steam for sauna.

Sauna stones are often overlooked but remain one of the most important parts of the sauna. Appropriate quality, size, and placement of stones in the heater can have a significant effect on the heat retention and steam generation in the sauna.

Sauna stones must be quarried and selected carefully to pass quality control, which confirms they are safe under intense heat and do not release any emissions. Harvia sauna stones are known to be safe under the intense temperatures of the sauna and retain heat for maximum efficiency.

All stones are thoroughly hand-selected and pre-washed so that replacing them is made easy every time. Prioritising sustainability, stones that don't meet the quality standards are repurposed for construction and other industries.

Note: Please refer to your sauna heater manual to determine the appropriate size stones.

Features

• Composition: Olivine diabase sauna stones are composed of a mixture of olivine and diabase, which are types of igneous rocks. This combination results in stones with unique properties and characteristics.
• Heat retention: Olivine diabase stones have excellent heat retention capabilities, allowing them to absorb and distribute heat effectively within the sauna. As a result they provide a consistent and comfortable sauna experience.
• Aesthetically pleasing: Traditional Finnish sauna stones have a natural beauty that enhances the visual appeal and natural ambiance in the sauna, elevating the overall experience.
• Improved steam: The heat-retaining properties of these stones contribute to efficient vaporisation of water. This in turn generates a pleasant and abundant steam in the sauna.
• Enhanced durability: These stones are known for their durability and hardness, making them long-lasting and resistant to cracking or breaking under high temperatures. Consequently, they can withstand a demanding sauna environment for longer.

Specifications

• Weight: 20 kg
• Brand: Harvia
• Stone size: 5-10 cm
• Colour: Grey
• Materials: Olivine diabase
• Origin: Finland

Did you know that electric heaters and wood-burning stoves must absolutely use massive, split-face sauna stones? The reason for this is that the split-face stones store plenty of heat, making the water thrown onto them vaporise efficiently on the broad fracture surface. The split-face stones are easy to stack and enable good air circulation, which saves the heating elements of an electric heater. Light (ceramic), soft (soapstone) and smooth (rounded) sauna stones do not produce the desired results. The split-face sauna stones by Harvia are selected with respect for old sauna traditions and provide bathers with proper, soft steam sensations.

Diabase, more commonly called Dolerite in the UK, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. A form of dolerite, known as bluestone, is one of the materials used in the construction of Stonehenge.

These traditional, high quality sauna stones are noted for their durability and excellent soft steam created when water is applied. These stones are can be fitted in any sauna heater. Each box comes with approximately 20 kg of premium Finnish olivine diabase sauna stones.

Stones should be filled to the rim but not exceed it and should be placed to maximise the space in between. This ensures a perfect loyly as the water can cascade easily down the length of the large heating capacity and allows air to flow between them with ease.

Over time, even the highest quality diabase fractures. Depending on usage, stones should be replaced once every year to every two years. This is important to maintain the voids between stones remain large enough for the through flow of water and air, and because the heat capacity of the stones relates to the size of the stones themselves.

For information on how to correctly load the stones into your heater, see our helpful video demonstration below:

How to check and maintain sauna heater stones?

Due to large variation in temperature, the sauna stones disintegrate slowly but gradually during use. Disintegrating stones can be observed if stone pieces are found on the floor of the sauna room. It is also advised to rearrange the stones at least once a year or even more often if the sauna is in frequent use. When rearranging, you should check the durability of the stones by hitting them together. If stones crack and sound shallow it is time to change disintegrated stones with new ones. Also remove any stone debris from the bottom of the heater.

How to pile sauna heater stones?

The piling of the sauna stones has a great effect on both the safety and the heating capability of the heater, especially for electric heaters. Always check the right heater stone size and amount from the manual included with the heater. Smaller 5-10 cm diameter stones are usually used in electric heaters as they fit well between heating elements. Smaller stone sizes are also used on the top layer of wood-burning heaters as they create more surfaces for steam generation. Larger 10-15 cm diameter stones are used in wood-burning heaters and also in selected Harvia electric heaters with larger stone capacity.

Start the stone piling by washing off the dust from the stones before placing them into the heater. Be aware, that the type and the shape of the heater affect the piling structure of the stones. Your best guide for doing this properly for your selected heater is to follow the instructions included in the heater manual. Here are a few important tips for piling sauna heater stones for all Harvia heater types.

• Do not drop stones into the heater
• Arrange the stones evenly and sparsely to make sure air can flow between the stones
• Do not form a high pile of stones on top of the heater
• Do not place stones on top of heater frame
• Place elongated stones vertically in the heater
• Also notice that in electric heaters:
• Do not wedge stones between the heating elements
• Pile the stones so that they support each other instead of lying their weight on the heating elements
• Support the heating elements with stones so that the elements don’t bend

New stones may give the sauna a natural stone scent during the first heating. After piling the stones, we recommend heating the sauna and throwing enough water to douse all the heater stones. By doing this the unwanted stone scent will be dispersed after the first heating.

Certification: Download Geological Survey of Finland report