What Kind of Cedar for a Sauna?
Western red cedar is a common sauna choice because it is light, stable and naturally aromatic. Choose clear boards for a cleaner look, or knotty boards when visible knots and a lower cost matter more.
On this page (7 sections)
- What kind of cedar for a sauna is most common?
- Is clear cedar worth choosing over knotty cedar?
- Which sauna cedar boards belong on walls, benches and backrests?
- How do you choose cedar boards for a sauna build?
- Can you use cedar fence boards or leftover lumber?
- Are cedar boards the right choice for every sauna?
- What kind of cedar should you choose for a sauna?
Western red cedar is a common choice for sauna boards because it is light, aromatic and often selected for its stability in a warm, humid room. Clear boards create a more uniform look; knotty boards show more natural variation and can be less costly.
Choose boards made for sauna interiors, then match the grade and surface to where each board will go. Benches and backrests need smooth, comfortable surfaces, while wall boards can prioritize appearance and budget.
What kind of cedar for a sauna is most common?
Western red cedar is the cedar most often associated with sauna construction. It offers a familiar reddish-brown color and a distinct aroma, though the exact appearance and scent vary from board to board.
Cedar is one option among several sauna woods. Our guide to what is the best wood for a sauna compares cedar with other common choices, while why saunas are made of wood explains how wood contributes to the room's surfaces and feel.
When shopping for sauna cedar boards, check the species, grade, dimensions, moisture condition and intended use. A label that only says “cedar” leaves important questions unanswered.
Which cedar species should you compare?
Western red cedar is a useful starting point for a traditional cedar interior. Other cedar species may be available, but names can vary by region and supplier, so confirm the wood species rather than relying on a general “cedar” label.
Ask the supplier for the botanical or commonly accepted trade name, whether the boards are intended for sauna interiors, and what grade they meet. If the wood is for a bench or backrest, also ask whether the grade excludes loose knots and other defects that could affect a skin-contact surface.
Is clear cedar worth choosing over knotty cedar?
Clear cedar is worth considering when you want fewer visible knots and a more consistent appearance. Knotty cedar is a practical option if you like its natural pattern and want to manage material costs.
“Clear” and “knotty” describe appearance and grade, not a guarantee that every board is flawless or suitable for every location. Check the boards for splits, loose knots, rough edges and other defects before installing them.
| Board choice | What it looks like | A practical fit |
|---|---|---|
| Clear cedar | More even, with fewer visible knots | A clean, uniform interior |
| Knotty cedar | Visible knots and more variation | A natural look with a tighter budget |
| Select or mixed grade | Varies by supplier and grade definition | Buyers willing to inspect boards individually |
Grade names and rules can differ among suppliers. Ask to see the grading description and sample boards, especially when appearance matters across a large wall.
For benches, avoid boards with loose knots, splinters or sharp edges. A lower-cost grade can still work if each board is sound, smooth and appropriate for the place it will be used.
Which sauna cedar boards belong on walls, benches and backrests?
Use boards with a smooth, splinter-free surface wherever your skin may touch them. Walls can use a wider range of visual grades, but boards still need to be sound, untreated and suitable for a hot, humid interior.
Bench boards need careful selection because you sit or lie against them. Look for even surfaces, rounded or eased edges, and no loose knots or rough patches.
For a bench upgrade or replacement, compare the dimensions and layout before buying a cedar sauna backrest.
Wall boards may be chosen more for appearance, but check for splits, excessive warping and defects that make installation difficult. Follow the sauna builder's directions for board spacing and fastening.
What surface finish should cedar sauna boards have?
A smooth, sanded surface is a sensible choice for benches, backrests and trim. It reduces the chance of splinters and feels more comfortable against skin.
For walls, a smooth surface is also easy to wipe down and gives a neat finish. Don't apply a paint, stain or sealant inside the sauna unless the product is specifically approved for sauna use and the sauna manufacturer allows it.
Inspect the boards after cutting and installation. Sand sharp corners and rough spots, then remove dust before using the sauna.
How do you choose cedar boards for a sauna build?
Choose cedar boards by matching the grade to their location, then confirm that the material is intended for sauna use. A simple checklist can prevent buying wood that looks right but needs extra work or doesn't fit the build.
If you are using cedar in a barrel build, see how to build a barrel sauna.
- Confirm the species. Ask for western red cedar or the exact species being sold.
- Ask about sauna suitability. Confirm that the boards are untreated and intended for an interior sauna.
- Choose a grade by location. Favor sound, smooth boards for benches and backrests; choose wall boards by appearance and budget.
- Check moisture and storage. Ask how the boards were dried and stored, and follow supplier guidance before installation.
- Measure before ordering. Confirm thickness, width, length and the amount needed, including waste from cuts.
- Inspect the actual boards. Look for splits, loose knots, roughness, cupping and inconsistent color.
- Plan around the heater. Follow its manual for wood clearances, wall assembly and installation.
If you are buying a finished cabin rather than lumber, our best cedar saunas for home guide compares complete options. For a larger cabin, see how to choose a four person western red cedar sauna.
Can you use cedar fence boards or leftover lumber?
Use fence boards only if the supplier confirms they are untreated and suitable for a sauna interior. Fence lumber may be rough, treated or sold at dimensions that don't fit sauna construction.
Never put pressure-treated, painted or chemically treated boards inside a sauna. Heat can change how materials behave, and coatings may release odors or fumes.
Leftover cedar can be considered if you know its species and treatment history, and can inspect its condition. Don't use boards with unknown coatings, persistent odors, mold, major splits or loose knots in skin-contact areas.
Are cedar boards the right choice for every sauna?
Cedar is a strong option when you want its color, aroma and familiar sauna appearance. It is not the only suitable wood, and some buyers may prefer a less aromatic species or a different price point.
Compare cedar with hemlock in our hemlock vs cedar sauna guide. If you are shopping for a ready-made unit, a wood-burning barrel sauna has different layout and material considerations from an indoor room.
These products serve different sauna-related needs, so check the use before choosing:
What kind of cedar should you choose for a sauna?
Choose western red cedar if you want the familiar cedar sauna look and aroma, then select clear or knotty boards based on appearance and budget. For benches and backrests, prioritize smooth, sound boards with no loose knots or splinters.
If you want a ready-made cedar cabin, compare its size and construction with your available space. You can also review Almost Heaven sauna models as a ready-made cabin option.
If you're building from boards, confirm species, treatment, grade, dimensions and heater clearances before ordering.
Frequently asked questions
What kind of cedar is best for a sauna?
Western red cedar is a common choice for sauna walls and benches because it is light, aromatic and often selected for its stability in changing heat and moisture. Compare the actual board grade, dimensions and intended use, since species name alone does not tell you whether a board is clear, knotty or suitable for a bench.
Is clear cedar better than knotty cedar for a sauna?
Clear cedar has fewer visible knots and gives a more uniform appearance, while knotty cedar keeps the natural knots visible and can cost less. Both can work for interior walls when the boards are suitable for sauna use; inspect each board for loose knots, splits and rough areas before installation.
Can you use cedar fence boards in a sauna?
Don't assume cedar fence boards are suitable for a sauna. They may be rough, treated, or sized for outdoor fencing rather than interior sauna use.
Check that boards are untreated, kiln-dried or otherwise suited to the sauna environment, and smooth enough for the surface where they'll be installed.
Should sauna boards be smooth or rough?
Use smooth, well-sanded boards on benches, backrests and other surfaces that touch skin. Walls can also be smooth for easier cleaning and a consistent finish.
Avoid splinters, sharp edges and rough patches, and follow the sauna heater and builder's instructions for clearances and materials.
Is cedar safe to use near a sauna heater?
Cedar is used in sauna interiors, but the heater's required clearances and installation rules still apply. Keep wood and other materials at the distances in the heater manual, and ask a qualified installer if the layout or wall assembly is unclear.
