ProSaunas Western Red Cedar Vertical Grain Sauna Boards, 1 x 4 (S4SEE, sold as clear grade A+)

1. Materials 45% of the rating 4 of 5

   Untreated Western red cedar, vertical grain and knot-free, from a maker that lists the treatment as “untreated” and its wood as selected from northern Europe and Canada; no grading rule, mill or emissions test is published, and cedar can trigger asthma in some people.

2. Durability 20% of the rating 4 of 5

   Vertical grain resists warping, the maker says Western red cedar resists decay and insects, and ProSaunas gives a two-year workmanship warranty through authorized resellers. At 0.69 in the boards are thin for bench stock, and Sauna Marketplace says cedar moves more with heat cycles than thermally modified wood.

3. Safety 10% of the rating 3 of 5

   The stores disagree on bench heat: Haven of Heat says cedar does not overheat, Sauna Marketplace says aspen stays noticeably cooler on bare skin; neither gives a measurement, and there is no fire or clearance guidance.

4. Trust 10% of the rating 3 of 5

   ProSaunas names species, treatment and a regional source and publishes a two-year workmanship warranty, but gives no grading rule, mill or certificate, and Haven of Heat says sauna wood is non-returnable. No recall or Prop 65 notice was found.

5. Value 15% of the rating 2 of 5

   About $25.60 per square foot at Sauna Marketplace ($7.48 per linear foot, plus $795 flat freight unless you order a heater) and $45 at Haven of Heat ($13.20), the most expensive wood we list either way, which a clear grade explains only in part.

The rating, 3.5 of 5, is the weighted average of these scores. See how we rank building a sauna and our standard.

• Haven of Heat (opens in a new tab) approx. $13.20 per linear foot ($52.80 for 4 ft, $79.20 for 6 ft, $132.00 for 10 ft). Calls it “clear grade A+” vertical grain cedar and says sauna wood is non-returnable. A different company from ProSaunas, which sells through resellers.
• Sauna Marketplace (opens in a new tab) approx. $7.48 per linear foot ($29.92 for 4 ft, $74.80 for 10 ft). Says knot-free vertical grain, “clear A+”, made in Canada, 0.69 in thick. Wood ships for a $795 flat rate per order, free with a heater order.

Prices as we saw them on October 23, 2026. They change often. These links carry no tracking code and earn us nothing.

1. Western red cedar, vertical grain; ProSaunas lists the treatment type as “untreated” and says it selects its wood from northern Europe and Canada; Sauna Marketplace says this board is milled in Canada
2. Smooth on four sides with eased edges (S4SEE); no glue, finish or treatment stated
3. Species and treatment named by the maker. “Clear A+” appears on the Haven of Heat and Sauna Marketplace pages, not on ProSaunas’ page, and no grading rule, mill or drying method is published

Is cedar a problem for people with asthma or wood allergies?

Western red cedar causes occupational asthma in some workers, as a follow-up of 125 patients shows (PubMed 7058838 (opens in a new tab)). We found no study of sauna users, so this is a precaution: if you have asthma or a wood allergy, ask your doctor, and consider alder or aspen.

Is “clear grade A+” a real grade, and where is it from?

ProSaunas’ own page (opens in a new tab) says vertical grain, untreated Western red cedar, selected from northern Europe and Canada. The grade name “clear A+” appears on the Haven of Heat and Sauna Marketplace pages, with no grading rule or mill; Sauna Marketplace adds that it is milled in Canada. Ask for a free sample before ordering, since Haven of Heat says sauna wood cannot be returned.

Does the finish or an oil go on it?

The maker lists the board as untreated and sells it smooth on four sides. Almost Heaven’s manual advises never treating a sauna interior unless the product is approved for saunas. Leave it bare or use only a product made for sauna use.

Is it worth the price?

At Sauna Marketplace it is $7.48 per foot against $5.70 for the 1.1 in thick Thermory thermo-aspen bench boards there; at Haven of Heat it is $13.20 against $12.65. The cedar is also thinner (0.69 in). We cannot say how much of the premium is the clear grade, and Sauna Marketplace itself says clear cedar runs about three times the price of thermo-aspen.

What does the maker cover?

ProSaunas’ limited warranty (opens in a new tab) covers defects in workmanship for two years of residential use, for products bought from an authorized reseller. It excludes natural wood variation, shrinkage and defects visible before installation. We could not confirm which stores are authorized resellers.

• Plain, named wood: untreated Western red cedar, vertical grain and knot-free, with no finish stated.
• The stores say cedar does not secrete resin and resists decay, which is why it is a classic sauna wood.
• Boards come smooth on four sides in lengths up to 10 ft, so benches and walls need little milling, and the maker publishes a two-year workmanship warranty.

• No grading rule, mill, drying method or certificate is published, and Haven of Heat says sauna wood is non-returnable.
• About $25.60 to $45 per square foot, the most expensive wood we list.
• Cedar can trigger asthma in some people (see the concern above).
• At 0.69 in thick it is thin for bench stock; Haven of Heat sells 2 in cedar for benches.

1. ProSaunas: Cedar 1x4 VG S4SEE. Maker’s page. Species, “untreated”, 0.69 x 3.5 in actual, wood sourced from northern Europe and Canada. Open ↗ (opens in a new tab)
2. ProSaunas limited warranty (Rev 4-26). Maker’s page. Two years against defects in workmanship, residential use, authorized resellers. Open ↗ (opens in a new tab)
3. Haven of Heat: ProSaunas vertical grain cedar 1x4 bench material. Independent source. Prices by length, “clear grade A+”, non-returnable, seen 2026-10-23. Open ↗ (opens in a new tab)
4. Sauna Marketplace: ProSaunas Western Red Cedar 1X4 VG S4SEE bench, backrest and skirting. Independent source. Price per linear foot, “made in Canada”, freight terms, seen 2026-10-23. Open ↗ (opens in a new tab)
5. Clinical features and natural history of occupational asthma due to western red cedar (Chan-Yeung 1982, PubMed 7058838). Independent source. Follow-up of 125 patients with red cedar asthma. Open ↗ (opens in a new tab)
6. Almost Heaven Blackwater owner’s manual (PDF). Maker’s page. Advises never treating a sauna interior unless the product is approved for saunas. Open ↗ (opens in a new tab)
7. US Consumer Product Safety Commission: recall search. Certifier or regulator listing. Returns no recall for ProSaunas (2026-10-23); searches for Haven of Heat and Sauna Marketplace also returned none. Open ↗ (opens in a new tab)
8. California Attorney General: Proposition 65 60-day notice search for ProSaunas. Certifier or regulator listing. No matching records (2026-10-23). Open ↗ (opens in a new tab)

• Thermory Alder Sauna Wall Boards (STS4) Untreated alder, about $3.62 to $5.76 per linear foot, with no cedar allergy issue.
• Thermory Thermo-Aspen Sauna Bench Boards (SHP) Heat-treated aspen for benches, about $5.70 to $6.84 per linear foot at two stores.

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