
Aspen 1x4 Nickel-Gap Tongue & Groove Paneling
Bold Style, Refined Finish
The Prosaunas Aspen 1x4 T&G STS4 panel brings a striking modern edge to any sauna interior. Its narrow, angular grooves deliver the sought-after nickel-gap look — clean, precise, and unmistakably contemporary. Mix it with other wood profiles to create a sophisticated contrast effect that elevates your space with a Scandinavian-inspired aesthetic.
Premium Aspen, Carefully Selected
Prosaunas handpicks straight-grained Aspen chosen for its uniform texture and elegant, light creamy color. Sourced from Northern Europe and Canada and backed by more than 55 years of sauna craftsmanship, every board meets stringent quality standards — so what arrives at your door is consistent, beautiful, and ready to impress.
Built for Sauna Walls & Ceilings
At 15 × 90 mm (292 mm length) with a classic tongue-and-groove fit, these panels are recommended for sauna walls and ceilings. Aspen's low heat conductivity means surfaces stay comfortable to the touch even in intense sauna heat, while its excellent dimensional stability and nail-friendly nature make installation straightforward and lasting.







Aspen 1x4 Nickel-Gap Tongue & Groove Paneling
Installation Required
Tongue-and-groove paneling is installed board by board onto wall studs or ceiling nailers, with each piece blind-nailed through its tongue to conceal fasteners. You will need basic carpentry tools and should acclimate the wood to your sauna environment before installation.
Description
Features
What's Included?
Size & Weight
Electrical Specs
Shipping & Delivery
Warranty
Documents
Description
This aspen tongue-and-groove paneling is milled to a 1x4 nickel-gap profile, meaning each board face measures roughly 90mm wide with a small reveal gap between boards once installed. That consistent spacing creates a clean, linear shadow line across your sauna walls and ceiling without requiring any additional trim work to achieve the look.
Aspen is a traditional Nordic sauna wood chosen for its low resin content, which keeps the surface from becoming tacky or discoloring under heat. It stays relatively cool to the touch even at high temperatures, making it a practical choice for benches, walls, and ceilings alike. The tongue-and-groove edges lock each board to its neighbor, holding the assembly flat and preventing warping as the wood cycles through heat and humidity.
Key Features
- Nickel-gap profile creates a consistent shadow-line reveal between boards, delivering a finished look without additional trim.
- Aspen's low resin content means the wood won't bleed sap or develop sticky spots under sauna heat — keeping surfaces clean and comfortable over time.
- Tongue-and-groove milling interlocks adjacent boards, which distributes seasonal wood movement evenly and helps the wall or ceiling panel stay flat.
- 1x4 nominal size (15mm × 90mm actual) offers a familiar board scale that works well on both walls and ceilings.
- Available in ten lengths from 1 ft to 10 ft, so you can select the board length that minimizes waste for your specific sauna dimensions.
1'
- 292 mm board length — suited to accent courses, small infill sections, or horizontal detail work where a short board is an advantage.
2'
- Approximately 610 mm board length — useful for compact wall sections and areas around doors or vents where longer boards would require excessive trimming.
3'
- Approximately 915 mm board length — a practical choice for bench backs and lower wall sections in smaller sauna cabins.
4'
- Approximately 1220 mm board length — a common selection for barrel sauna interiors and prefab sauna kits with standard 4 ft panel runs.
5'
- Approximately 1525 mm board length — spans a typical sauna wall section with fewer end joints, keeping the finished surface visually cleaner.
6'
- Approximately 1830 mm board length — aligns with standard 6 ft wall height applications, allowing a full-height run with a single board and no horizontal seam.
7'
- Approximately 2135 mm board length — suited to slightly taller sauna interiors where a 6 ft board would fall short of a full-height run.
8'
- Approximately 2440 mm board length — matches standard North American stud spacing, simplifying layout when running boards vertically on 8 ft walls.
9'
- Approximately 2745 mm board length — useful for ceiling runs in wider sauna rooms where shorter boards would introduce a visible mid-span butt joint.
10'
- Approximately 3050 mm board length — the longest option in this range, ideal for uninterrupted ceiling or wall runs in larger custom sauna builds.
Size & Weight
Dimensions
15 × 90 mm
Product Width
3.54" (90mm)
Shipping Length
Up to 10'
SHIPPING & DELIVERY
Sauna wood is not free shipping. Length, piece count, profile, and weight set the rate. These are the Bathing Brands contiguous-US flat rates. Canada is the same table plus $100. Alaska, Hawaii, and remote addresses are quoted.
Checkout charges the 8' piece-count table (contiguous US). Canada is the same table plus $100. Boards over 8' use that same checkout rate; dock or liftgate extras are a follow-up. Alaska, Hawaii, and remote addresses are quoted.
BOARDS UP TO 8'
Under 40 pieces generally ships FedEx Ground in cardboard. Over 40 pieces generally ships LTL with a liftgate on a wood pallet. The longest board in the order sets the rate tier.
- Under 19 boards — $195
- 20–39 boards — $395
- 40–99 boards — $495
- 100–299 boards — $695
- 300–499 boards — $895
- 500–799 boards — $995
- 800–999 boards — $1,295
BOARDS OVER 8' UP TO 10'
These lengths ship LTL on a wood pallet. They do not qualify for a liftgate — you need a dock, machinery, or hand offload on site. Carriers allow about one hour to unload before extra fees.
- Under 19 boards — $295
- 20–39 boards — $495
- 40–99 boards — $595
- 100–299 boards — $795
- 300–499 boards — $995
- 500–799 boards — $1,095
- 800–999 boards — $1,395
HOW THIS SHIPS
- We pack for a safe arrival at the lowest rate that fits the order.
- Boards over 8' carry a surcharge because long crates cost more to move than a standard skid.
- Heaters, doors, or accessories on the same order can offset some of that freight.
Description
Description
This aspen tongue-and-groove paneling is milled to a 1x4 nickel-gap profile, meaning each board face measures roughly 90mm wide with a small reveal gap between boards once installed. That consistent spacing creates a clean, linear shadow line across your sauna walls and ceiling without requiring any additional trim work to achieve the look.
Aspen is a traditional Nordic sauna wood chosen for its low resin content, which keeps the surface from becoming tacky or discoloring under heat. It stays relatively cool to the touch even at high temperatures, making it a practical choice for benches, walls, and ceilings alike. The tongue-and-groove edges lock each board to its neighbor, holding the assembly flat and preventing warping as the wood cycles through heat and humidity.
Features
Key Features
- Nickel-gap profile creates a consistent shadow-line reveal between boards, delivering a finished look without additional trim.
- Aspen's low resin content means the wood won't bleed sap or develop sticky spots under sauna heat — keeping surfaces clean and comfortable over time.
- Tongue-and-groove milling interlocks adjacent boards, which distributes seasonal wood movement evenly and helps the wall or ceiling panel stay flat.
- 1x4 nominal size (15mm × 90mm actual) offers a familiar board scale that works well on both walls and ceilings.
- Available in ten lengths from 1 ft to 10 ft, so you can select the board length that minimizes waste for your specific sauna dimensions.
1'
- 292 mm board length — suited to accent courses, small infill sections, or horizontal detail work where a short board is an advantage.
2'
- Approximately 610 mm board length — useful for compact wall sections and areas around doors or vents where longer boards would require excessive trimming.
3'
- Approximately 915 mm board length — a practical choice for bench backs and lower wall sections in smaller sauna cabins.
4'
- Approximately 1220 mm board length — a common selection for barrel sauna interiors and prefab sauna kits with standard 4 ft panel runs.
5'
- Approximately 1525 mm board length — spans a typical sauna wall section with fewer end joints, keeping the finished surface visually cleaner.
6'
- Approximately 1830 mm board length — aligns with standard 6 ft wall height applications, allowing a full-height run with a single board and no horizontal seam.
7'
- Approximately 2135 mm board length — suited to slightly taller sauna interiors where a 6 ft board would fall short of a full-height run.
8'
- Approximately 2440 mm board length — matches standard North American stud spacing, simplifying layout when running boards vertically on 8 ft walls.
9'
- Approximately 2745 mm board length — useful for ceiling runs in wider sauna rooms where shorter boards would introduce a visible mid-span butt joint.
10'
- Approximately 3050 mm board length — the longest option in this range, ideal for uninterrupted ceiling or wall runs in larger custom sauna builds.
What's Included?
Size & Weight
Size & Weight
Dimensions
15 × 90 mm
Product Width
3.54" (90mm)
Shipping Length
Up to 10'
Electrical Specs
Shipping & Delivery
SHIPPING & DELIVERY
Sauna wood is not free shipping. Length, piece count, profile, and weight set the rate. These are the Bathing Brands contiguous-US flat rates. Canada is the same table plus $100. Alaska, Hawaii, and remote addresses are quoted.
Checkout charges the 8' piece-count table (contiguous US). Canada is the same table plus $100. Boards over 8' use that same checkout rate; dock or liftgate extras are a follow-up. Alaska, Hawaii, and remote addresses are quoted.
BOARDS UP TO 8'
Under 40 pieces generally ships FedEx Ground in cardboard. Over 40 pieces generally ships LTL with a liftgate on a wood pallet. The longest board in the order sets the rate tier.
- Under 19 boards — $195
- 20–39 boards — $395
- 40–99 boards — $495
- 100–299 boards — $695
- 300–499 boards — $895
- 500–799 boards — $995
- 800–999 boards — $1,295
BOARDS OVER 8' UP TO 10'
These lengths ship LTL on a wood pallet. They do not qualify for a liftgate — you need a dock, machinery, or hand offload on site. Carriers allow about one hour to unload before extra fees.
- Under 19 boards — $295
- 20–39 boards — $495
- 40–99 boards — $595
- 100–299 boards — $795
- 300–499 boards — $995
- 500–799 boards — $1,095
- 800–999 boards — $1,395
HOW THIS SHIPS
- We pack for a safe arrival at the lowest rate that fits the order.
- Boards over 8' carry a surcharge because long crates cost more to move than a standard skid.
- Heaters, doors, or accessories on the same order can offset some of that freight.
Warranty
Documents
Explore Compatible Heaters
Learn more


Aspen 1x4 Nickel-Gap Tongue & Groove Paneling


Aspen 1x4 Nickel-Gap Tongue & Groove Paneling


Aspen 1x4 Nickel-Gap Tongue & Groove Paneling


Aspen 1x4 Nickel-Gap Tongue & Groove Paneling


Aspen 1x4 Nickel-Gap Tongue & Groove Paneling


Aspen 1x4 Nickel-Gap Tongue & Groove Paneling
Design
DIMENSIONS
Model: Aspen 1x4 Nickel-Gap Tongue & Groove Paneling
Nominal size: 1x4 (15mm x 90mm)
Length per piece: 1', 2', 3', 4', 5', 6', 7', 8', 9', 10'
Weight: 1–10 lb (0.45–4.54 kg)
MATERIALS
Species: Aspen
Finish: Natural/Unoiled
Thickness: .59" (15mm)
Prosaunas
Built by Sauna Artisans
From Western Red Cedar to Himalayan salt, every material is chosen by our team of sauna artisans — because "Perfection in Sauna" is the standard we build to, not just a tagline.
Prosaunas
Everything Your Sauna Needs, One Source
Wood, doors, windows, lighting, salt, care products — Prosaunas outfits every detail of your build, backed by a nationwide dealer network.
Prosaunas
Real Experts, Real Answers
Questions about materials or installation? Our Wheeling, Illinois-based team is here Monday–Friday, and every build is backed by our workmanship warranty.
DELIVERY & INSTALL
Delivery
Assembly
Install
Delivery
Assembly
Install
Let customers speak for us
from 59 reviews
Everything as advertised. Easy set-up and a great addition to our sauna. I had a few questions and received prompt replies and great customer service. I would order again.
FD-3 Full Spectrum Infrared Sauna
Absolutely stellar interaction with Mitch. Cannot thank them enough. Would do business again without a thought in the matter!
Mitch and the team were incredibly thoughtful and patient while I worked on my order. Shipping was clear and conciencias and everything arrived as it should
Communication and attention to customer service was amazing!!!
Love our large sauna! Actually put it together by myself.....was not recommended but can be done! Exactly as advertised! Great service!
This is a great cedar-sided cold plunge tub. I spent a considerable amount of time researching cold plunge tubs and wanted one with real ceder wood to fit my sauna room. It also has a durable heat pump, compared to lower-quality chillers. I have had it a few months and no issues. Also, in the pics below, I have the chiller, which is about a 2' x 2' cube plumbed to a different space for a clean sauna room look. I would highly recommend this tub and the price is less than some on the market.
These guys are AMAZING! I’d leave 10 stars if I could. We purchased a barrel sauna and cold plunge from them in fall 2025. They were absolutely terrific to work with! Our contractor and electrician had many (many) questions, all were promptly and kindly answered. They even customized our order by selling an extra long cord so we could install control panel inside for extra protection in MN winters. Shipping and delivery was a breeze. We are using our sauna daily and love it! Zero hesitation recommending this company! Thank you Johnny and Mitch for all your help!!!
These guys are AMAZING! I’d leave 10 stars if I could. We purchased a barrel sauna and cold plunge from them in fall 2025. They were absolutely terrific to work with! Our contractor and electrician had many (many) questions, all were promptly and kindly answered. They even customized our order by selling an extra long cord so we could install control panel inside for extra protection in MN winters. Shipping and delivery was a breeze. We are using our sauna daily and love it! Zero hesitation recommending this company! Thank you Johnny and Mitch for all your help!!!
Researched many saunas for many months. Finally landed on this one. Only complaints i have are the instructions weren't very well written and the trim on the outside was very difficult to put together. We use it almost daily.
Super stoked about the new sauna. I ended up with a beautiful 2-3 person cedar sauna with a huum heater. It’s perfect. These guys were helpful in choosing the right size, type, etc.
very glad I used the cold plunge guys.
Received order quickly. Great service
Had a great experience working with the Cold Plunge Guys and would highly recommend their products!
Honest, knowledgeable and reliable. I appreciate all the care that goes into each personal interaction.
I ordered my heater on a Thursday and it arrived the following Tuesday.
The price was by far the lowest I was able to find. I am super impressed with this company.
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