Leil Saunas Black Cube Comfort - 6 Person Outdoor Traditional Sauna Kit
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An Important Note on Pricing and Returns:
We believe in upfront pricing and fair policies—no hidden fees, no surprises, and easy,
transparent returns. If you're comparing options, we encourage you to review
competitors’ fine print carefully.
We've helped countless customers who had issues elsewhere, and we’re here to make sure
that never happens to you.
Starts at: $2,372.50/mo Learn More
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LEIL BLACK CUBE COMFORT
6-Person Outdoor Sauna Kit
More space. Built for shared sessions.
The Black Cube Comfort is designed for people who actually want to use their sauna together. With a deeper layout and opposing bench design, it creates a more open interior where conversations flow and seating feels natural—not cramped. It comfortably fits up to six adults while maintaining consistent, full-body heat throughout the cabin.
Built from 40mm thermowood for outdoor durability and paired with black tempered glass for a clean, architectural look, it balances modern design with real sauna performance. Ships as a DIY-friendly kit, with most customers assembling it over a weekend. Just bring a second set of hands and a drill—leave the heater hookup to a pro.
Built for shared sessions. Designed to feel open.
A social sauna that doesn’t feel crowded.
Most larger saunas add seats but lose the experience. Benches line the walls, people face forward, and the space feels tighter than it should. The Black Cube Comfort takes a different approach. With a deeper footprint and opposing bench layout, it creates a more open, face-to-face environment—built for conversation, shared sessions, and longer time inside without feeling boxed in.
The exterior keeps the bold Black Cube silhouette, while the interior stays warm and natural with thermowood walls and Alder benches. Heat circulates evenly across both sides, so whether you’re stretching out or sitting across from someone, the experience stays consistent throughout the cabin.
- Opposing bench layout for a more social, face-to-face sauna experience
- 40mm thermowood walls for durability and stable heat retention outdoors
- Full black tempered glass front with matching minimalist exterior details
- Optional LED lighting and rear window upgrades for added ambiance
Technical Specifications
Every measurement, every material, every rating — in full detail.
Which heater fits the Black Cube — Harvia or HUUM?
HUUM DROP 6 kW
Included in Select Packages- Best for: Standard back wall construction (no panoramic window)
- Output: 6 kW — ideal for the Black Cube's 5 m³ volume
- Control: UKU Classic Wi-Fi controller included
- Style: Minimalist drop-shaped design with large stone capacity
- Why it works: The DROP's stone basket holds more rocks than comparably sized heaters, producing a softer, more even löyly (steam). Wi-Fi control via the HUUM app lets you preheat remotely.
HUUM DROP 9 kW
Recommended — Half-Panoramic Window- Best for: Black Cube with optional half-panoramic back wall window
- Output: 9 kW, accounts for additional heat loss from the panoramic glass
- Control: UKU Classic Wi-Fi controller included
- Style: Same drop design, larger capacity
- Why it works: The panoramic window adds significant glass area. The 9 kW ensures the sauna reaches and holds target temperature even in colder climates without overworking the heater.
Harvia KIP80W (8 kW)
Reliable Alternative- Best for: Buyers who want a simple, proven electric heater
- Output: 8 kW — balanced performance for this sauna size
- Control: Built-in controls (wall-mounted optional upgrade)
- Style: Traditional wall-mounted steel heater design
- Why it works: A dependable, no-frills option from a long-standing Finnish brand. Heats consistently, installs easily, and is ideal if you prefer straightforward operation over app-based control.
Will it fit your space? We’ll help you plan it right.
Share your patio, deck, or backyard measurements and we’ll map out exactly how the Black Cube Comfort fits— including door swing, clearance zones, and optimal placement for ventilation and heater safety. No guessing before delivery.
Two people. Weekend build.
The Black Cube Comfort arrives as a pre-cut, pre-labeled outdoor sauna kit designed for straightforward DIY assembly. Most of the structure can be completed with basic tools, while the final electrical hookup must be completed by a licensed professional.
Two people, a drill, a level, and basic hand tools. No special equipment required.
What’s in the Kit
Every component is pre-cut, labeled, and engineered for modular assembly. All hardware and documentation are included for a smooth installation process.
- 40mm Thermowood wall panels, base frame, and roof structure
- Black shingle roof system for full weather protection
- 8mm black tempered glass front wall and door assembly
- Two-level Alder wood benches with skirts and backrests
- Nerostep anti-slip plastic grid floor mats
- Full-circle front and rear arch panels (painted black)
- Integrated ventilation system (3–4 openings)
- All fasteners, mounting hardware, and step-by-step manual
Assembly Steps
Prepare a Level Foundation
Choose a flat, stable outdoor surface such as a concrete slab, reinforced deck, or compacted gravel base. Ensure proper drainage and maintain clearance around all sides for airflow and maintenance access.
Unpack & Verify Components
Lay out all labeled components and cross-check with the included parts list before starting assembly to ensure nothing is missing or damaged during transport.
Assemble Base, Walls & Roof Structure
Construct the base frame first, then attach the thermowood wall panels in sequence. Install the roof structure, followed by the shingle layers for full weather protection and insulation.
Install Glass, Benches & Interior Elements
Mount the black tempered glass front and door system, then install the opposing Alder bench seating, backrests, ventilation covers, and floor grid system.
Licensed Electrician Connects Heater
The heater requires a dedicated 240V electrical connection with appropriate breaker sizing based on the selected unit (6 kW, 8 kW, or 9 kW). This step must be completed by a licensed electrician in accordance with local electrical codes and manufacturer specifications.
Initial Heat Cycle & Break-In
Run the first heating cycle with the door slightly open to allow materials to settle. A mild natural wood and heater odor may be present initially and will dissipate after the first few uses.
Yes, it runs on 240V —
and we make it simple.
The Black Cube Comfort uses a standard residential 240V hardwired sauna heater circuit, similar to what powers an electric dryer or oven. Depending on your selected heater (6 kW, 8 kW, or 9 kW), the system typically requires a 20–40 amp dedicated breaker. A licensed electrician can complete installation in roughly 1–2 hours.
From our warehouse to your driveway.
The moment you order, your concierge rep is assigned and your shipment starts moving. We monitor every stage so you don't have to. Fully insured, with a scheduled delivery appointment so nothing arrives when you're not home.
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Good luck getting
Costco on the phone.
Most $8,000 purchases come with a phone tree. Ours comes with a person. When something goes sideways — a lost shipment, a freight delay, a damaged panel, a question at 9 PM on a Wednesday — you text us. We text back. Same day, often the same hour. We call the manufacturer. We chase the freight company. We solve the problem while you go on with your life. That's what we mean by boutique concierge service. It's the difference between buying a sauna and being supported through one.
Lost in Transit
If your shipment goes missing, we're on the phone with the freight carrier before you even know there's a problem. You don't chase anyone. We do.
Shipping Delays
You hear about delays from us, before you wonder. We monitor every shipment, every day, until it's in your driveway.
Manufacturer Defect
If a panel arrives damaged or a heater malfunctions, we escalate directly to Leil, HUUM, or Harvia on your behalf. You don't make a single warranty call. We handle the back-and-forth.
A Question at 9 PM
Text us. Email us. Call us. You get a real answer from a real person — not a chatbot, not a ticket number, not a 48-hour response window.
We're not the cheapest box on the internet. We're the team that picks up the phone after the box is in your driveway. That's what we stand behind — every order, every customer, every day.
Call (605) 702-4868Yes, it's outdoor rated. Built for year-round use.
Yes. The Black Cube Comfort is fully engineered for permanent outdoor installation in all weather conditions. Rain, snow, humidity, and seasonal temperature swings are all accounted for in the construction. The structure is designed to stay stable and weather-resistant without annual sealing or protective re-coating, while still delivering consistent sauna performance inside the cabin.
Thermally treated wood resists moisture absorption, warping, and decay. It is dimensionally stable in outdoor environments and does not require chemical treatment or seasonal refinishing.
Heavy-duty bitumen shingle roofing protects against rain, UV exposure, and snow load, ensuring long-term durability in exposed outdoor conditions.
The base frame is raised and isolated from direct ground contact, preventing moisture transfer and improving airflow beneath the structure.
Structural reinforcement and tensioning components help the cabin adapt to seasonal expansion and contraction without compromising alignment or sealing.
Built-in gravity ventilation openings maintain airflow without fans or electronics, supporting consistent heat circulation and long-term reliability outdoors.
Alder wood benching, tempered black glass, and heater-ready stone volume are all designed for real sauna use. The interior is built to handle high heat and humidity cycles without degradation over time.
Built to survive outdoors. Designed to feel warm inside.
The Black Cube Comfort uses a dual-wood system designed specifically for outdoor sauna performance. Thermowood forms the structural shell, engineered to withstand constant exposure to weather and heat cycles, while Alder is used for all interior contact surfaces to ensure comfort, safety, and a premium sauna feel at high temperatures.
Thermowood — 40mm Exterior Shell
The walls, roof structure, base frame, and exterior elements are constructed from heat-modified softwood. The thermal modification process permanently alters the wood’s cellular structure, reducing moisture absorption and increasing resistance to rot, fungi, and deformation. This makes it highly stable in outdoor environments without chemical treatments.
Alder — Interior Bench System
All seating surfaces are crafted from kiln-dried Alder, selected for its low thermal conductivity and smooth grain. It remains comfortable to touch even at high sauna temperatures, making it ideal for extended sessions and multi-person use in a 6-person layout.
Black Exterior Finish System
External accents, including base frame, arches, and moldings, are finished in a weather-resistant black coating system. This protects exposed surfaces from UV degradation and moisture while giving the Black Cube its signature architectural aesthetic.
Outdoor Longevity Engineering
The wood system is designed for freeze-thaw cycles, humidity swings, and year-round outdoor exposure. Combined with proper ventilation and elevated base design, it maintains structural integrity without seasonal sealing or refinishing requirements.
Open the crate. Everything is pre-cut and labeled.
The Black Cube Comfort ships as a complete modular sauna kit. All structural components are pre-cut, pre-labeled, and engineered for straightforward assembly. Heater and electrical accessories depend on the configuration selected at checkout.
Thermowood Structural Kit
40mm thermally treated wood panels for walls, roof sections, base frame, and structural supports — all pre-cut and labeled for fast assembly.
Heater (Selected Configuration)
HUUM DROP 6 kW, HUUM DROP 9 kW, or Harvia KIP80W 8 kW depending on package selection. Includes stones and compatible mounting hardware (controller included for HUUM models).
Alder Bench System
Two-level opposing bench layout in solid Alder wood with backrests, skirts, and precision-cut supports for a 6-person seating configuration.
Complete Hardware Pack
Structural fasteners, steel tension bands, screws, bolts, washers, ventilation covers, bitumen roof underlay, and sealing materials for full outdoor assembly.
Black Tempered Glass Assembly
8mm black tempered glass front wall and door system with premium handle set and matching black exterior framing components.
Installation Manual
Step-by-step assembly guide with labeled diagrams, part indexing, electrical guidance overview, and foundation preparation instructions.
Frequently Asked Questions
Everything you need to know before ordering your sauna.
Exterior: 86.2" W × 89.0" D × 86.6" H.
Wall thickness: 40mm thermowood.
Interior volume: approximately 7.8 m³.
Manuals & Resources
Everything you need for assembly, electrical, and ongoing maintenance — in one place.
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