What Cedar for a Sauna? Western Red, Yellow or Eastern Red

Western red cedar is the best cedar for a sauna: it is light, stays comfortable to touch, resists rot, and sauna makers say it does not secrete resin. Alaskan yellow cedar is a solid second choice, but eastern red cedar (the closet-lining kind) is a poor fit for a hot room. This guide compares real density and hardness numbers, knots, and safety.

Cedar Sauna Basics: Why the Species Matters

A sauna is a hard place for wood. It swings between dry heat and steam, it gets wet, and you sit on it with bare skin. Three things decide whether a cedar works in that job: how it holds up against moisture, how hot the surface feels, and what it releases when heated.

Western red cedar checks all three boxes, which is why it shows up in most premium traditional saunas. Sauna makers point to its natural oils as protection against humidity and long-term wear, and to the fact that it does not secrete resin or overheat. For a deeper look at how the species behaves in general, see our guide to what cedar wood is used for.

One thing worth clearing up: “cedar” on a lumber rack does not mean one wood. Western red cedar, Alaskan yellow cedar and eastern red cedar are three different species with very different weights and hardness, and they are not interchangeable in a sauna. Our comparison of eastern vs western red cedar covers the split in more detail.

Cedar Types Compared: The Numbers

These figures come from the Wood Database. The last column is a simple ratio I calculated against western red cedar to show how different the woods really are.

Species	Janka hardness	Density	Decay resistance	vs western red (density)
Western red cedar	350 lbf	23 lbs/ft3	Durable to very durable	baseline
Alaskan yellow cedar	580 lbf	31 lbs/ft3	Durable to very durable	about 35% denser
Eastern red cedar	900 lbf	33 lbs/ft3	Excellent	about 43% denser

The surprise for most buyers: eastern red cedar is about 2.6 times harder than western red cedar (900 vs 350 lbf), yet it is the one people associate with the strong cedar smell. Hardness is not what you want in a sauna. Sauna makers favor light, low-density woods because they feel cooler against the skin, which is the same reason aspen and hemlock are popular. Density is a rough proxy here, not a measured heat test, so treat it as a guide.

Which Cedar Fits Your Sauna? A Quick Decision Table

Your situation	Best pick	Why
Indoor traditional sauna, benches and walls	Clear western red cedar	Lightest of the three, gentle on bare skin, decay resistant
Bench that takes heavy daily use	Alaskan yellow cedar	580 lbf vs 350 lbf, so it dents less
Outdoor sauna cladding on a budget	Knotty western red cedar	Knots are fine away from seating
Sensitive to cedar dust or scent	Aspen or hemlock	Milder, no resin, no plicatic acid concern
Closet or chest lining	Eastern red cedar	Strong scent, but not a sauna wood

Western Red Cedar: The Standard Choice

Western red cedar is the default because its weakness (softness) barely matters on a wall, and its strengths matter a lot. It has a Janka hardness of only 350 lbf and a basic specific gravity of 0.31, so it is one of the lightest commercial softwoods. The Wood Database rates it durable to very durable for decay resistance, which is what you want when steam condenses on the boards every session.

The trade-off is that it dents and scratches very easily. Bench edges, the corner where you drop a bucket, and any spot that takes a knee will show wear. That is cosmetic, not structural, and many owners simply accept it as patina. If you plan to finish or oil the surface, read whether cedar needs to be finished first, because sauna interiors are normally left bare.

Grades and knots

Cedar is sold as clear (few or no knots) or knotty. For walls and ceilings, knotty is common and cheaper. For benches, backrests and anywhere skin lands, clear is the safer choice: a knot can loosen as it shrinks and swells through repeated heat cycles, and a raised or loose knot on a seat is a splinter waiting to happen. This is general trade advice rather than something I measured, so ask your supplier about their grading.

Thickness and profile

Wall and ceiling cedar is commonly sold as 1×4 or 1×6 tongue and groove paneling, roughly three quarters of an inch thick. The tongue and groove profile hides the joints and lets boards move a little as they swell and dry. Bench slats need more thickness than wall panels because they carry weight, so buy bench lumber rather than reusing paneling offcuts. Always confirm the spec against your sauna kit or heater manual.

Alaskan Yellow Cedar: The Tougher Alternative

Alaskan yellow cedar has a Janka hardness of 580 lbf and a density of 31 lbs/ft3, so it resists dents better than western red cedar. The Wood Database lists it as durable to very durable and easy to work, and notes that skin irritation has been reported, though severe reactions are uncommon. It is a sensible pick if you want bench lumber that does not scar as quickly, or if you are building the sauna outdoors where weather adds to the wear.

The catch is that it is heavier, so it will not feel quite as gentle to sit on as western red cedar, and it is usually harder to find in sauna kits. If you can only get one species locally, western red is the easier and more traditional path.

Eastern Red Cedar: Why It Is the Wrong Pick

Eastern red cedar, also called aromatic red cedar, is the wood used to line closets and cedar chests. According to the Wood Database it is dense (900 lbf), commonly knotty, comes in narrow boards, and has been reported to cause skin and respiratory irritation. Its strong aroma comes from natural extractives that repel moths.

For a sauna, that combination is unappealing: knots in the seating zone, a hard surface, and a scent designed to be strong, which heat tends to intensify. I did not find any sauna manufacturer that recommends it, and the makers I read all point to western red cedar (and alternatives like aspen and hemlock). I am not claiming it is dangerous in a sauna, only that there is no good reason to use it when better woods exist. If you want that scent for a closet instead, see the best cedar for closets and what cedar smells like.

Heat, Moisture and Safety Notes

• Do not seal the surface. Bare wood stays comfortable to touch. Films and varnishes can blister and soften under heat.
• Watch surface heat on hardware. Metal screws and nails in a bench can become uncomfortable to touch in a hot room, so recessed or hidden fasteners are the usual approach.
• Ventilate. Cedar can take steam, but it still needs airflow to dry. Read our note on whether cedar can get wet and the wider guide to wood for high-moisture areas.
• Protect yourself when building. Western red cedar contains plicatic acid, which the Wood Database links to allergic reactions and occupational asthma. Wear a respirator when cutting or sanding it, and sweep dust up rather than blowing it around.
• Follow your heater manual. Clearance rules around the stove come from the manufacturer, not from the wood species.

Measuring the room helps you catch problems early. A basic sauna gauge, like the one above, shows temperature and humidity so you know when the room is running hotter or wetter than your build was designed for. If you are curious how long cedar lasts in general, see how long cedar wood lasts.

Cedar Alternatives for Saunas

Cedar is not required. Sauna makers also use aspen (no resin, splinters or excess heat, with a smooth light tone), Canadian hemlock (radiates heat evenly, soft and knot-free) and radiata pine (recommended for benches by at least one maker). If cedar allergies are a concern, aspen or hemlock are the practical swaps. The trade-off is scent: cedar brings a distinct aroma, while these woods are milder.

Frequently Asked Questions

What type of cedar is best for a sauna?

Western red cedar is the standard choice. It is light (about 23 lbs per cubic foot), it does not secrete resin or overheat according to sauna makers, and it is rated durable to very durable against decay. Alaskan yellow cedar is a good, denser alternative.

Is eastern red cedar safe to use in a sauna?

Eastern red cedar is not what sauna builders normally use. It is dense (900 lbf Janka), usually knotty, and reported to cause skin and respiratory irritation. I did not find a sauna maker source that recommends it, so choose western red cedar or Alaskan yellow cedar instead.

Is knotty or clear cedar better for a sauna?

Clear (knot-free) cedar is the safer choice for benches and backrests, because your bare skin touches them. Knotty cedar is common on walls and ceilings and looks rustic, but knots can loosen or shrink as the wood cycles through heat, so keep them away from seating.

What thickness of cedar should I use for a sauna?

Sauna cedar is commonly sold as 1×4 or 1×6 tongue and groove paneling, which is about three quarters of an inch thick. Benches are usually built from thicker lumber so they stay rigid under body weight. Check your sauna kit or heater manual for its exact requirements.

Can cedar cause allergies in a sauna?

Western red cedar contains plicatic acid, which is linked to allergic reactions and occupational asthma, mostly in people who cut and sand it. Sitting in a finished sauna is a different exposure, but if you are sensitive to cedar, choose aspen or hemlock and wear a dust mask when working the wood.

For most builders the answer is simple: choose clear western red cedar for benches and backrests, use knotty grades only where skin does not touch, and step up to Alaskan yellow cedar if you want a harder surface. Leave eastern red cedar for the closet.