Sauna Stones

Sauna stones store heat from your heater and release it as steam when you ladle water over them. The right stones produce a soft, even cloud of steam called löyly, while the wrong ones give a harsh, short-lived blast that fades fast.

Vulcanite absorbs heat slowly and releases it evenly, which makes the steam softer and longer-lasting than from quick-heating stones. It also resists cracking and splintering through repeated wet-dry heat cycles, so the stones last longer and don't shed sharp fragments into your heater.

Most sauna owners replace stones every 1 to 3 years depending on use. Signs it's time: steam feels weak, stones look crumbly or cracked, or dust collects in your heater. Frequent users replace yearly, while casual once-a-week users can stretch closer to three years.

Check your heater's manual for capacity, usually given in pounds or kilograms. Most standard electric and wood-burning home heaters take 20 to 40 lb. Our 33 lb Kivi™ box fills most home heaters in a single purchase, with extras for replacements over time.

Place smaller stones at the bottom for stability and larger ones on top, where they meet the ladled water. Leave space between stones so air and water can move through. Avoid packing tight, since airflow is what lets stones heat evenly and produce clean steam.

Löyly is the Finnish word for the wave of steam that rises when water meets hot sauna stones. It describes both the steam itself and the soft, enveloping feel of a well-run sauna. Good stones and slow, controlled ladling produce the best löyly.