Cedar vs hemlock for a sauna interior: an honest comparison
Western red cedar and Canadian hemlock solve different problems in a sauna. Grain, resin, scent, heat behaviour, and durability under commercial use — and why we stock hemlock and offer cedar.
Cedar and hemlock are the two timbers serious sauna builders argue about, and the argument is worth having properly: they behave differently at 90°C, age differently under seven-nights-a-week use, and suit different buyers. We build our interiors in Canadian hemlock and offer a Western red cedar upgrade — here is the reasoning on both sides, including the case against our own default.
Canadian hemlock: the commercial-duty answer
Hemlock is close-grained, low-resin, and pale — and each of those adjectives is doing engineering work.
Close grain means dimensional stability: through thousands of heat-and-humidity cycles, tongue-and-groove boards stay seated instead of cupping or opening at the seams. On a public calendar this is the difference between a cabin that looks new at year five and one that looks tired at year two.
Low resin means no sap bleed at temperature and — critically for bare skin — a surface that stays comparatively cool to the touch even when the air is at 100°C. Resinous softwoods can weep and can bite.
Neutral scent and colour cut both ways. Hemlock lets the löyly — the steam — carry the sensory experience, and its pale, even face suits an architectural interior. But it will never give you the perfumed hit cedar people love. That’s the honest trade.
Ours is PEFC chain-of-custody certified, milled at 21 mm tongue-and-groove (full specification).
Western red cedar: the sensory answer
Cedar’s case is aroma and warmth of colour, and it’s a real case. The oils that scent a cedar sauna are also naturally rot- and insect-resistant, and the reddish, variegated face reads rich and traditional. For a private owner who wants the cabin to smell like a sauna the moment the door opens, cedar is the right call — it’s why we offer it as a named interior upgrade (+$9,720 on our cabin).
The costs of that choice, stated plainly: cedar is softer (benches dent and wear faster under high traffic), the aromatic oils fade over years of hard use, its colour variation is a taste rather than a neutral, and those same oils are a mild sensitiser for a small minority of skins — worth knowing if the cabin serves the public. And it is meaningfully more expensive.
The rule of thumb
- Public or hospitality duty — booked sessions, daily cycling, mixed guests: hemlock. Stability and neutrality are worth more than perfume at commercial frequency.
- Private cabin, sensory priority: cedar earns its premium every time the door opens.
- Allergy-adjacent or clinical settings: hemlock, without much debate.
What matters more than the species
Whichever timber wins your argument, three things matter more: milling (21 mm T&G holds heat and stays seated; thin cladding doesn’t), certification (chain-of-custody paperwork is how you know what you actually bought), and what’s behind the boards — insulation, membrane, and frame decide whether the interior’s microclimate is stable enough for either species to live long. The interiors that fail early usually fail behind the timber, not in it.
And one materials position we hold at any price: no MDF, no plywood, no particle board anywhere in a heat cabin — bonded boards off-gas at temperature. The full list of what we refuse to specify is on the craft page.