A sauna is heated to 80–90°C and cooled again every session, in Indonesia’s heat and humidity. The wood decides how it feels, how long it lasts and what it costs to run.
Why a partnership
We researched building saunas of our own. It didn’t make sense. Partnering with Sozen, a maker who builds to the standard of our stainless steel ice baths, did.
The vacuum kiln
The only saunas in Indonesia made this way
The outside is mahogany. Sozen heat-treats it at 180–200°C in a vacuum kiln. With no air inside, the wood cannot catch fire, so it takes heat that would burn it in an ordinary kiln. The cedar inside is left fully natural.
Sozen is the only importer of this wood in Indonesia, and the only company here with the machine for this process.
Vacuum kiln · Kaido with Sozen
180–200°C
In a vacuum, so the wood cannot burn. Treated evenly, right through the board.
Ordinary kiln · most makers
Hot air
Air in the kiln, so the wood can catch fire at that heat. Treated from the outside in.
Inside: natural Canadian red cedar
Untreated, and it smells like it
The cedar inside is left fully natural. Its own oils resist rot and termites, so it needs nothing on it, and the room keeps the scent of real cedar. It barely moves, too: about 1.2% and 2.6% shrinkage from green to 12% moisture.
Clear grade: no knots
Clear is the top grade of red cedar, and it costs on average twice as much as knotty cedar.
The grade
What red cedar costs, a square foot
On average twice the price
Cedar against sungkai
Sungkai is what many saunas in Indonesia use inside.
Weight
A cubic metre, dried
Lighter is better: cooler to touch
About 40% lighter
Insulation
How well a 40 mm wall keeps the heat in
Higher is better: costs less to run
About 65% better
Durability
Rated life above ground
Longer is better
2–3× as long
Outside: thermo-mahogany
A harder-wearing wood, heat-treated
The outside is not cedar. It takes the rain and the sun, so it is clear-grade mahogany (meranti), heat-treated at 180–200°C in a vacuum kiln, with no chemicals. It comes in two finishes: scorched black, or darkened to a deep brown.
Outside
Heat-treated against untreated wood (untreated = 100)
Lower is better
Holds less water, so it swells, shrinks and rots less
What it means to run one
- Heats sooner: about 15 kg of cedar in each square metre of wall, against 26 kg of sungkai.
- Costs less to run: the walls keep more heat in, so the heater works less.
- Lasts longer: rated 15–40 years above ground, against 7–15 for sungkai.
Before you go in
Never alone. With a heart condition, high blood pressure or pregnancy, talk to a doctor first.
To ask about a sauna, or a sauna with a Kaido ice bath, send us an enquiry.