Cedar vs Hemlock Sauna - Which Is Better and Which Looks More Premium?

Updated October 16, 2026. Every wood rating, study and product page cited below was re-checked on that date.

Cedar vs. Hemlock Sauna: The Short Answer

Cedar. Western red cedar is rated durable to very durable, Japanese cedar moderately durable to durable, and both carry aromatic heartwood compounds with documented antifungal and antibacterial activity. Hemlock is rated non-durable, has no characteristic odor, and western hemlock is the same species sold as Hem-Fir framing lumber; its one published advantage is hardness. Sun Home builds no sauna in hemlock.

About this comparison: Sun Home sells saunas built in cedar and eucalyptus and does not sell hemlock, so we have a commercial interest in this question. For that reason, every material claim below is tied to a published wood-science reference or a live product page, each re-checked on October 16, 2026, and the limits of the evidence are stated in the open. Where a point is our editorial judgment rather than a measured property, we say so.

What Is the Difference Between Cedar and Hemlock?

In the sauna trade, "cedar" means one of two aromatic conifers in the cypress family (Cupressaceae): western red cedar (Thuja plicata), grown in the Pacific Northwest and British Columbia and often sold as Canadian red cedar, or Japanese cedar (Cryptomeria japonica, also called sugi). "Hemlock" means one of two Tsuga species in the pine family: western hemlock (Tsuga heterophylla) or eastern hemlock (Tsuga canadensis), which The Wood Database lists under the common name Canadian hemlock.

The split is clean. Both cedars are rated at least moderately durable against decay (western red cedar durable to very durable, Japanese cedar moderately durable to durable) and both are aromatic. Both hemlocks are rated non-durable, have no characteristic odor, and are sold mainly as construction lumber: The Wood Database lists their common uses as boxes, pallets, crates, plywood and framing, and notes that western hemlock is milled together with five fir species and sold under the generic HEM-FIR stamp.

Those ratings belong to the species, not to a lumber grade. Clear, knot-free hemlock boards exist and are what a sauna interior would be cut from; a cabin built from them is still built from a species rated non-durable and odorless. Grade governs knots and appearance. It does not change heartwood chemistry, and nothing in this article depends on which grade a given brand buys.

Cedar vs. Hemlock: Property-by-Property Comparison

Ratings and figures below are published values from The Wood Database (species pages re-checked October 16, 2026) and the peer-reviewed studies listed in the sources section. Janka hardness is measured at 12 percent moisture content.

Why Is Hemlock Rated Non-Durable?

Because decay resistance comes from heartwood chemistry, and on that measure hemlock rates poorly. The USDA Forest Products Laboratory's research note on comparative decay resistance explains that resistance to decay rests only in the heartwood, where natural preservatives are usually stored. Cedar heartwood is loaded with them. A 1997 study in Wood and Fiber Science (DeBell, Morrell and Gartner) states that western red cedar's high decay resistance comes from toxic extractives called tropolones in its heartwood, and found decay resistance uniformly high once tropolone content reached 0.25 percent. We found no published characterization of protective extractives in hemlock heartwood comparable to cedar's tropolones; what the references do establish is the rating that results, with The Wood Database listing both commercial hemlocks as non-durable and susceptible to insect attack.

This has been measured directly. In a 2022 Oregon State University study published in Frontiers in Forests and Global Change, untreated western hemlock blocks in a standard AWPA E10 soil-block test lost 49.5 percent of their mass on average across three decay fungi in 16 weeks, and 57 to 62 percent to the two brown-rot fungi. Under the ASTM D2017 scale the authors used, anything over 45 percent loss is slightly or non-resistant. Read that for what it is: a laboratory method in which small blocks are wetted to 30 to 40 percent moisture content and set on fungus-colonized feeder strips. It measures how a species holds up once its wood is wet, not the lifespan of a finished cabin. The USDA note gives the service-life version of the same gap: untreated posts with very resistant heartwood may last 20 years or more, while posts with non-resistant heartwood might last five years or less.

What that means inside a sauna: decay needs sustained moisture, and the USDA note is explicit that a species' decay resistance matters where conditions favor decay. A dry indoor cabin that is wiped down after every session may not reach those conditions often in either wood. The point of a durable species is what happens on the days it does: a bench or floorboard that stays damp, the steam of a traditional sauna, an outdoor cabin in weather. In those conditions cedar carries a documented chemical defense, and hemlock carries a non-durable rating, which is the measured result of whatever its heartwood holds. The rating is a property of the species; grade, kiln-drying and finish change appearance and stability, not heartwood chemistry.

Is Cedar Antimicrobial?

Yes, in the sense that matters for a wood: cedar heartwood carries natural antimicrobial compounds, and the evidence is peer-reviewed.

• Western red cedar. Its tropolones include beta-thujaplicin, also known as hinokitiol. A 2007 study in the Journal of Chemical Ecology (Manter, Kelsey and Karchesy) tested heartwood extracts from seven western conifers and found western red cedar and incense cedar showed the strongest antimicrobial activity against the plant pathogen Phytophthora ramorum, with hinokitiol among the most active compounds. A 2026 study in Pathogens from Wroclaw Medical University, which identifies beta-thujaplicin as a heartwood component of Thuja plicata, reports in-vitro bactericidal activity against most tested Streptococcus strains and summarizes prior literature showing antibacterial activity against both Gram-positive and Gram-negative bacteria.
• Japanese cedar. A 2006 study in the Journal of Wood Science (Matsushita and colleagues) isolated sandaracopimarinol and ferruginol from sugi heartwood and found moderate antifungal activity against three fungi plus strong antibacterial activity against Gram-positive bacteria.
• Hemlock. We found no comparable published characterization of protective heartwood compounds, and the species is rated non-durable and susceptible to insects. Absence of a study is not proof of absence; the rating is the firm part.

What we do not claim: these are laboratory studies of extracted compounds, not tests of finished sauna boards, and no study shows that a cedar cabin sanitizes itself. Wipe your sauna down after every session regardless of wood. The point is narrower and firmer: the compounds that make cedar resist fungi and decay are documented, and no equivalent has been documented for hemlock, whose rating reflects that.

Why Do Budget Saunas Use Hemlock?

Because it is a commodity construction species. The Wood Database describes western hemlock as construction lumber sold under the HEM-FIR label alongside firs, and eastern hemlock as a construction timber in good supply, with both at moderate prices for a domestic softwood. The same reference notes that clear, straight-grained grades of western red cedar can cost more than construction-grade cedar, and sauna interiors are typically built from clear boards.

On the published record, hemlock's case comes down to price plus one property: it tests harder than cedar on the Janka scale (540 lbf for western hemlock against 350 for western red cedar). Against that, it is rated non-durable where cedar is rated durable, susceptible to insects where cedar's resistance is rated mixed to moderate, and odorless where cedar is aromatic. That is why we read a hemlock spec as a cost decision. It is also a species comparison, not a grade comparison: a clear hemlock board is still a non-durable, odorless softwood.

One verified example of where the wood ends up: the Dynamic "Barcelona" 1-2 person far-infrared sauna, listed at $2,099 on the brand's own store on October 16, 2026, carries "natural hemlock wood construction" in its feature list (product page). That is one listing, not a survey. We cite it because it states the wood plainly, and because it matches where we most often see hemlock specified: cabins where price is the headline. Treat that last clause as our observation, not a market statistic.

A note on the label "Canadian hemlock." It sounds like a grade. It is a trade name: The Wood Database lists Canadian hemlock as a common name for eastern hemlock. A spec sheet rarely says which Tsuga species is inside the cabin, and for this comparison it does not need to, because both commercial hemlocks carry the same non-durable rating and the same "no characteristic odor" entry. The word "Canadian" does not change a single property in the table above.

Does Hemlock Smell Like Cedar?

No. The Wood Database records western red cedar as having a strong, lingering, aromatic scent and sugi as having a distinct, lingering, cedar-like odor. Its entry for both commercial hemlocks reads "no characteristic odor." The scent and the durability come from the same heartwood oils, so a hemlock cabin gives up both at once. Some buyers do want an unscented interior; hemlock delivers that, as any odorless softwood would, and it is a preference rather than a performance property. For everyone else, the aroma of a warming cedar cabin is part of what they are paying for. That last sentence is editorial; the odor ratings are not.

Is Hemlock Harder Than Cedar, and Does That Matter?

Yes, and the gap is not trivial on paper. Western hemlock tests at 540 lbf and eastern hemlock at 500 lbf on the Janka scale, against 350 lbf for western red cedar and 320 lbf for Japanese cedar: roughly 40 to 70 percent higher depending on the pair. That is hemlock's one published advantage, and it is real; The Wood Database notes that western red cedar dents and scratches very easily because of its softness. Two things keep it in proportion. First, all three are soft softwoods: on The Wood Database's hardness tiers, hemlock's 2,400 newtons still lands in the "very low" band. Second, hardness does not buy durability. Durability is heartwood chemistry, and hemlock's hardness edge comes packaged with a non-durable rating, insect susceptibility and no scent. If dent resistance is what you want from a bench, the place to look is a hardwood rather than a harder softwood. Sun Home uses kiln-dried eucalyptus, a hardwood, in the Equinox line; its product pages do not state the eucalyptus species, so this article does not print a Janka or decay figure for it, and "hardwood" here is a botanical class, not a performance score. All three softwoods in the table are low-density, which is the general reason softwood is used for sauna surfaces that touch skin.

Which Wood Looks More Premium in a Home?

The color facts are published; the design read is ours. Western red cedar heartwood runs reddish to pinkish brown with random darker streaks and bands. Japanese cedar heartwood is reddish brown with clearly demarcated straw-colored sapwood. Hemlock is light reddish brown. In a living space, that warmth and variation is what reads as a chosen material, the way walnut or teak does. Hemlock's pale uniformity reads as construction lumber because construction lumber is its primary job. If you want a pale interior, choose a species on purpose for that look; do not accept it as the byproduct of a cost cut.

Can Hemlock Be Used for an Outdoor Sauna?

Untreated and exposed to weather or persistent moisture, no: non-durable plus insect-susceptible is the wrong combination for that exposure. An outdoor cabin with a weather-tight exterior shell changes what the interior boards see; it does not change the species rating of the boards you sit on, and condensation and sweat still reach them. Some outdoor sauna brands sell thermally modified hemlock, marketed as thermowood, to work around that. The 2022 Oregon State study tested one such process: western hemlock run through a thermal-modification cycle peaking at 170°C still lost 50 to 52 percent of its mass to the two brown-rot fungi in 16 weeks and remained non-resistant to both. The authors called the improvement modest, nowhere near as effective as preservative treatment, and expected a hotter cycle to do better, so the result speaks to that process rather than to every thermally modified product on the market. What it does establish is that heat treatment is a workaround for a species rated non-durable, and that the workaround is not guaranteed. Western red cedar, by contrast, is rated durable to very durable, and The Wood Database lists shingles, exterior siding and boatbuilding among its common uses for exactly that reason. Sun Home's outdoor Luminar pairs a Canadian red cedar interior with an aluminum exterior; our outdoor sauna cost-of-ownership guide compares aluminum, cedar and thermowood exteriors in detail.

Which Wood Does Sun Home Use?

Sun Home does not build any sauna in hemlock. Interiors of our infrared saunas and the Nova are cedar or eucalyptus, model by model, exactly as published on each product page on October 16, 2026:

Cedar and eucalyptus are, in our view, the gold standard for premium sauna interiors, and that is the standard every model above is built to: a durable, aromatic cedar or a hardwood, not hemlock. How the cabins are built is covered on our craftsmanship page, and the full lineup is in the home sauna collection.

Bottom Line

Cedar wins on decay rating, protective heartwood chemistry, insect rating and scent. Hemlock wins on Janka hardness and on price, and the lumber references explain the price: western hemlock is the same species sold as HEM-FIR construction lumber. If a sauna's spec sheet says hemlock or Canadian hemlock, you are looking at a material whose published case rests on price and hardness and which trails cedar on every durability and scent rating, and you will live with it on every bench, backrest and floorboard for the life of the cabin. Buy cedar, or a hardwood like eucalyptus, and read the wood line on the spec sheet before you read anything else.

Frequently Asked Questions

Is hemlock a good wood for a sauna?

Not compared with cedar. Hemlock is rated non-durable against decay and susceptible to insect attack, has no characteristic odor, and is the same species sold as construction lumber for boxes, pallets, crates, plywood and framing. Its one published advantage is Janka hardness (540 lbf for western hemlock against 350 for western red cedar); every durability-related rating trails cedar.

Why do cheap saunas use hemlock?

Because hemlock is a commodity construction species, with western hemlock sold under the HEM-FIR stamp with firs, and lumber references list it at moderate prices, while clear grades of cedar can cost more. In our reading, choosing hemlock lowers material cost; on the published ratings it adds hardness and nothing else, and it gives up the decay rating, the insect rating and the scent.

Is Canadian hemlock better than regular hemlock?

No. The Wood Database lists Canadian hemlock as a common name for eastern hemlock (Tsuga canadensis), which it rates non-durable and susceptible to insect attack with no characteristic odor; western hemlock carries the same ratings. "Canadian" is a trade name, not a grade or a species upgrade.

Is cedar antimicrobial?

Cedar heartwood carries natural antimicrobial compounds: tropolones such as beta-thujaplicin in western red cedar, and sandaracopimarinol and ferruginol in Japanese cedar. Peer-reviewed lab studies document antifungal and antibacterial activity for these compounds. Those are tests of extracts and compounds, not finished sauna boards, so wipe down any sauna after use.

Does a hemlock sauna smell like cedar?

No. The Wood Database lists western red cedar as strongly aromatic and Japanese cedar as having a distinct, cedar-like odor, while both commercial hemlocks have no characteristic odor. A hemlock cabin smells like warm lumber.

Is hemlock hypoallergenic?

Not on the published references, and neither is cedar. The Wood Database reports skin and respiratory irritation and runny nose for western hemlock, skin irritation for eastern hemlock, and documents western red cedar dust as an occupational allergen. Every one of those reports concerns woodworking and dust exposure; none measures the risk of sitting in a finished cabin of either species, so this article draws no comparative allergy conclusion. If you have a known wood sensitivity, sit in a cabin before you buy one, whatever the wood.

Is Japanese cedar a real cedar?

Neither Japanese cedar nor western red cedar is a true cedar of the genus Cedrus. Both are aromatic conifers in the cypress family, which is what "cedar" means in the lumber trade. The Wood Database notes that, like most cedars, sugi is soft, light, aromatic and resistant to decay, and rates it moderately durable to durable.

Is eucalyptus better than hemlock for a sauna?

Only partly answerable from published data. Eucalyptus is a hardwood by botanical class; hemlock is a softwood rated non-durable with no characteristic odor. Sun Home's product pages do not state the eucalyptus species used in its Equinox and Solstice saunas, so this article does not assign it a Janka or decay rating. What is established is which wood Sun Home uses in its infrared and Nova saunas and which it does not: eucalyptus and cedar, not hemlock.

Can a hemlock sauna go outdoors?

Untreated hemlock exposed to weather or persistent moisture is the wrong choice: it is rated non-durable and susceptible to insect attack. Inside a weather-tight enclosure the question becomes moisture management rather than weather, and the species rating still applies to the interior boards. One thermal-modification process tested in a 2022 Oregon State study (a cycle peaking at 170°C) left western hemlock non-resistant to brown-rot fungi; hotter cycles were not tested. Western red cedar is rated durable to very durable and is a standard exterior wood.

Sources and Verification

Evidence labels: [Reference] is a published wood-properties reference; [Peer-reviewed] is a journal study; [Manufacturer page] is a live product page quoted for what it states. All links checked October 16, 2026.

1. [Reference] The Wood Database, Western Red Cedar (Thuja plicata): decay rating, insect resistance, odor, color, Janka hardness, dried weight, common uses, pricing note on clear grades, allergy note.
2. [Reference] The Wood Database, Western Hemlock (Tsuga heterophylla): non-durable rating, insect susceptibility, no characteristic odor, HEM-FIR grouping, common uses, pricing, irritation reports.
3. [Reference] The Wood Database, Eastern Hemlock (Tsuga canadensis): common name Canadian hemlock, non-durable rating, no characteristic odor, construction-timber use.
4. [Reference] The Wood Database, Sugi / Japanese Cedar (Cryptomeria japonica): moderately durable to durable rating, cedar-like odor, color, Janka hardness, dried weight, cypress-family note.
5. [Reference] USDA Forest Service, Forest Products Laboratory, Research Note FPL-0153, Comparative Decay Resistance of Heartwood of Native Species (1967): decay resistance rests in heartwood extractives; service-life comparison for resistant versus non-resistant heartwood.
6. [Peer-reviewed] DeBell, Morrell and Gartner, Tropolone Content of Increment Cores as an Indicator of Decay Resistance in Western Redcedar, Wood and Fiber Science 29(4), 1997.
7. [Peer-reviewed] Presley, Cappellazzi and Eastin, Durability of Thermally Modified Western Hemlock Lumber Against Wood Decay Fungi, Frontiers in Forests and Global Change 5:813080, 2022: soil-block mass-loss data for untreated and thermally modified western hemlock.
8. [Peer-reviewed] Manter, Kelsey and Karchesy, Antimicrobial Activity of Extractable Conifer Heartwood Compounds Toward Phytophthora ramorum, Journal of Chemical Ecology 33:2133, 2007.
9. [Peer-reviewed] Marcinów, Piątkowska and Kujawa, Anti-Streptococcal Activity of beta-Thujaplicin, Pathogens 15(9):978, 2026.
10. [Peer-reviewed] Matsushita and colleagues, Antimicrobial activity of heartwood components of sugi (Cryptomeria japonica) against several fungi and bacteria, Journal of Wood Science 52:552, 2006.
11. [Manufacturer page] Sun Home product pages for Eclipse, Pod, Luminar, Nova, Equinox and Solstice: interior wood by model.
12. [Manufacturer page] Dynamic Saunas Direct, Barcelona DYN-6106-01 product page: "natural hemlock wood construction," $2,099 list price on the check date.

Review scope: the expert-verification credit above covers the health and allergy statements in this article, and the fact-check credit covers the citations, figures and product-page statements against their sources. No wood scientist or materials engineer reviewed this article; the wood-property statements are quoted from the references named rather than assessed independently.

What this article does not include: no original decay, moisture or microbial testing was performed on sauna boards for this comparison; every durability and antimicrobial statement above is a published rating or study result, cited to its source.

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