Sauna Stones - Grade A Finnish Olivine Diabase 20 kg

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. They are available in two sizes: 5-10 cm and 10-15 cm. In the case that heaters require both grades, larger stones should be used at the base with smaller grade stones added to the top of the heater. Each box comes with approximately 20 kg of premium Finnish olivine diabase sauna stones.

For both wood burning and electric sauna heaters, stones should be filled to the rim but not exceed it. Stones should be placed to maximise the space in between. This ensures a perfect löyly 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. A simple way to check yourself is to measure the stones in comparison to your closed fist, once stones become smaller than this, they should be replaced.

For information on how to correctly load the stones into your heater, see our helpful guide including video demonstrations available here.

Please note that as a natural material, there may occur some colour variation between the stones.

The differing stone size requirements for each stove can be found below:

Check out our following guides on how to arrange, check and change your sauna stones: 

• How to correctly arrange the stones in your sauna heater
• 4 important questions answered about sauna stones

Christmas and New Year's Delivery Notice

Please note the following changes to our pallet shipping and DPD delivery service on parcel orders over the Christmas period.

Our warehouse is fully closed for operation over the following days: Wednesday 24 December, Thursday 25 December, Friday 26 December, Wednesday 31 December and Thursday 1 January.

Orders requiring a pallet

The last dispatch date for orders requiring a pallet is Friday 19th December 2025. Pallet orders dispatched on this day must be booked and signed for with one of our sales team representatives latest by close of business on Friday 19th December 2025.

Please note:

• Pallets dispatched on 19th December will be delivered on either 22nd or 23rd December, depending on your postcode
• We strongly advise against booking deliveries to the Highlands or Channel Islands close to the 19th December, as these may be held at the hub over the festive period
• There may be limited availability for pallet shipping on this day and we cannot guarantee that available slots remain

We will commence our regular pallet shipping service on Monday 5th January 2026.

If you have any questions about your pallet order, please get in touch with our Sales team: +44 (0) 20 8050 2895 or email info@finnmarksauna.com

Small Parcel Orders

DPD will deliver as normal up to and including Tuesday 23rd December 2025. Orders for next day delivery must be placed latest by 3pm.

Limited dispatch service: We will dispatch DPD orders on Monday 29th December and Tuesday 30th December only during the festive closure period.

We will commence our regular delivery service on Monday 5th January 2026.

*Estimated delivery times are applicable to the UK mainland only (excludes Highlands and Islands). Additional delays and charges will be required for Non-UK Mainland and Highlands and Islands deliveries.