Plain facts on rocks for sauna heaters
Sauna heater stones, explained plainly
This site is about the rocks inside a sauna heater. It covers which kinds exist, what size to buy, how to load them, and when to swap or clean them. Every page points back to the heater maker's own guidance.
It's for anyone with an electric or wood-fired sauna heater who wants to look after the stones properly.
All the stone pages
Sauna stone types comparedWhich kinds of rock makers sell for sauna heaters, how they differ, and why picking stones off the ground is a bad idea.
Peridotite, olivine and diabase stonesWhat the rock names on sauna stone bags mean, and what heater makers say about olivine diabase and other heater stones.
What size should sauna stones be?Typical heater stone sizes in centimetres, why small stones suit electric heaters, and how makers layer sizes for steam.
How many stones does a heater hold?Find the stone weight your sauna heater needs from its manual, with examples from one maker and what overloading does to airflow.
How to load and stack heater stonesHow to place sauna stones around the elements so air can pass, with the do's and don'ts two heater makers publish.
When to replace sauna stonesSigns of worn heater stones, how to test them, and the replacement and re-stacking intervals that Harvia and HUUM publish.
Cleaning sauna stonesHow to clear dust and residue off heater stones with water and a soft brush, and when to replace a stone instead of cleaning it.