ProSaunas — Sauna-Grade Wood, Vapor Barrier & Building Materials

ProSaunas supplies premium sauna-grade lumber and building materials for custom DIY sauna builds. If you're building a sauna room from scratch — framing out a closet, basement, bathroom, or outdoor structure — ProSaunas provides the wall cladding, bench boards, trim molding, vapor barrier, and lighting you need to finish the interior. All ProSaunas wood is specifically graded and selected for sauna use: kiln-dried, smooth-sanded, and free of the resins and knots that cause problems in high-heat environments. Available in multiple wood species and profiles to match your design vision. Free shipping on all ProSaunas products, 0% APR financing available.

Planning a custom sauna build? Our complete DIY sauna room kits bundle all the materials you need in one package. If you prefer to source individual components, browse the ProSaunas catalog below.

Wall & Ceiling Cladding

ProSaunas offers wall and ceiling cladding in multiple wood species and joint profiles. Cladding is the interior surface material that covers your framed and insulated sauna walls — it's what you see and touch when you're inside the sauna. Choose your wood species based on aesthetics, aroma preference, and budget, then select a joint profile that matches your design style.

Cedar Cladding — Clear Grade A+ Western Red Cedar with vertical grain. Cedar is the classic sauna wood — naturally aromatic, moisture-resistant, and decay-resistant with a warm reddish-brown color. Available in 1"×4" Nickel Gap (narrow groove between boards for a modern look), 1"×4" V-Gap (traditional V-joint), 1"×6" V-Gap (wider boards), and 1"×4" Tongue & Groove profiles. Shop all sauna wood.

Hemlock Cladding — Canadian Hemlock with a clean, straight grain and light straw color. Hemlock doesn't warp in sauna conditions, radiates heat evenly, and produces a delicate, relaxing aroma that's subtler than cedar. A popular choice for buyers who want a lighter, more neutral interior. Available in 1"×4" Bead Gap and 5/8"×4" V-Joint profiles.

Thermo-Aspen Cladding — Heat-treated aspen with improved dimensional stability and moisture resistance. The thermal treatment darkens the wood to a rich brown tone. Available in 1"×4" Nickel Gap and 2"×3" Large Gap (a dramatic wide-groove profile for a bold design statement).

Thermo-Spruce Cladding — Thermally modified spruce with the same stability benefits as thermo-aspen in a slightly different grain character. Available in 1"×4" Nickel Gap.

Thermo-Radiata Pine Cladding — Thermally treated radiata pine with distinctive grain character. Available in 1"×4" Nickel Gap.

Alder Cladding — A smooth, warm-toned hardwood that stays cool to the touch. Available in 1"×4" Nickel Gap. Alder is a traditional European sauna wood known for its even heat distribution and attractive grain.

Aspen Cladding — Light, smooth wood that stays cool to the touch. Available in 1"×4" Nickel Gap. Aspen is hypoallergenic and scent-neutral — a good choice if you want a minimal-aroma sauna interior.

Bench Material

Bench boards need to be smooth, splinter-free, and made from wood that doesn't overheat against bare skin. ProSaunas offers bench lumber in multiple species and dimensions for building custom bench frames, seating surfaces, and support structures.

Cedar Bench Material — Clear Grade A+ Western Red Cedar in 1"×4", 1"×4" Rough 1 Side (for a textured grip), 1"×6", 2"×4" (for bench framing and seating), 2"×12" (wide bench planks), and 4"×4" (structural support posts).

Thermo-Aspen Bench Material — Available in 1"×4", 5/4"×3", 5/4"×4" dimensions. Aspen stays cool to the touch even at high sauna temperatures, making it one of the most comfortable bench woods. The thermo treatment adds durability and a darker tone.

Alder Bench Material — Available in 5/4"×6". Alder's smooth texture and cool-touch properties make it a premium European choice for bench surfaces.

Aspen Bench Material — Available in 1"×4". Untreated aspen for a light, natural finish.

Thermo-Radiata Pine Bench Material — Available in 5/4"×6". A distinctive grain with thermo-treated durability.

Molding & Trim

ProSaunas carries trim molding to finish edges, corners, and transitions in your sauna build. Available in species that match the wall cladding options so you can create a cohesive interior.

Vapor Barrier

Every sauna room needs a vapor barrier between the insulation and the interior cladding to prevent moisture from penetrating the wall cavity. ProSaunas offers sauna-specific aluminum foil vapor barrier in two sizes: a 4' × 80' roll (320 sq ft) for smaller projects and a 4' wide roll covering 1,300 sq ft for larger builds. The foil barrier reflects radiant heat back into the sauna room (improving energy efficiency and reducing heat-up time) while blocking moisture migration. This is one of the most-searched ProSaunas products — vapor barrier for saunas pulls over 8,300 impressions in search.

Lighting

LED Light Kit — A flexible 16' LED strip light kit designed for sauna installation. Creates ambient indirect lighting behind benches, along ceilings, or around the perimeter of your sauna room. Available in white. Sauna lighting needs to be rated for high-heat environments — standard LED strips will fail in sauna conditions. The ProSaunas kit is purpose-built for sauna temperatures.

Frequently Asked Questions

Which wood should I choose for my sauna walls?

Cedar is the most popular choice — aromatic, naturally moisture-resistant, and the classic sauna look and smell. Hemlock is a clean, neutral alternative if you prefer a lighter color and subtler scent. Thermo-aspen and thermo-spruce are thermally treated for enhanced stability with a darker, modern aesthetic. Alder and aspen are European favorites that stay cool to the touch. Your choice is primarily aesthetic and aromatic — all of these woods are rated for sauna use and will perform well.

Which wood is best for sauna benches?

The most important factor for bench wood is heat absorption — you want a species that doesn't get uncomfortably hot against bare skin. Aspen (including thermo-aspen) and alder are the coolest-touch options. Cedar is popular for benches too and performs well, though it runs slightly warmer than aspen. Avoid dense hardwoods or resinous softwoods (like pine or spruce) for bench surfaces — they get too hot or can secrete sticky resin at sauna temperatures.

What's the difference between V-Gap, Nickel Gap, and Tongue & Groove?

These are joint profiles — the way boards fit together on the wall. V-Gap (V-Joint) creates a small V-shaped groove between boards for a traditional sauna look. Nickel Gap leaves a narrow flat reveal between boards for a cleaner, more modern aesthetic. Tongue & Groove (T&G) fits boards flush with minimal visible gap for the smoothest wall surface. All three are structurally sound — the choice is purely visual preference.

What else do I need to build a custom sauna?

A complete custom sauna build requires: framing lumber (standard construction lumber, not sauna-specific), insulation (mineral wool or fiberglass rated for high-heat), vapor barrier (the ProSaunas foil barrier on this page), wall and ceiling cladding, bench material, trim molding, an electric sauna heater or wood-burning stove, a sauna door, ventilation, lighting, and 240V electrical. If you'd rather get everything in one order, our complete DIY sauna room kits bundle all the sauna-specific components together. Use our heater sizing calculator to match the right heater kW to your room's cubic footage.

How do I calculate how much wood I need?

Measure your sauna room's wall and ceiling area in square feet, then add 10–15% for waste and cuts. Cladding boards are sold by linear foot — the product pages include coverage calculations. For bench material, plan your bench layout (how many tiers, bench depth, and total length) and calculate board feet from there. If you need help with material estimates, call or text our team at (360) 233-2867.

Shop more: All Sauna Wood · Bench Wood · DIY Sauna Room Kits · Electric Sauna Heaters · Wood-Burning Stoves · Heater Packages · Heater Sizing Calculator