SaunaLife Model S4B 6-Person Wood-Burning Black Hot Tub

 

 

A timeless, off-grid soaking tub designed for deep relaxation, natural heat, and shared ritual.

 

 

The SaunaLife SOAK-Series Model S4B is a premium wood-burning outdoor hot tub designed for those who value simplicity, craftsmanship, and the elemental pleasure of water and fire.

 

Fully assembled and requiring no electricity, this eco-friendly hot tub delivers a deeply restorative soaking experience powered entirely by wood heat. With space for up to six bathers, a generously sized interior holding over 304 gallons of water, and a contoured fiberglass lining for comfort, the S4B transforms any backyard, cabin, or retreat setting into a place of warmth, connection, and calm.

 

 

 

 

Model	Model S4B
Material	Thermo-Spruce
Interior Dimensions	71" Diameter x 33"D
Exterior Dimensons	79" Diameter x 37"H
Water Capacity	304 Gallons
Product Weight when filled	3064 lbs
Stove Dimensions	19.8"L x 11.8"W x 13.1"H
Chimney Dimensions	95"H x 4.7" Diameter
Maximum Wood Length	16"
Maximum Temperature	106F
Shipping Dimensions	91"L x 46"W x 87"H
Shipping Weight	595 lbs

 

 

 

 

 

Model S4B Outdoor Wood-Burning Hot Tub

   

• Thermo-Spruce materials (lasts up to 2X longer than Cedar)  
• Luxury outdoor wood-burning hot tub 
• Designed for outdoor ergonomic hot tub bathing experiences 
• Arrives fully assembled and no electricity required (eco-friendly) 
• Spacious interior holds over 304 gallons of pure water bathing pleasure 
• Thick dark grey contoured fiberglass lining provides enhanced bather comfort 
• Stainless steel wood-burning heater utilizes dual heat compartments for unmatched efficiency   
• Rapid response heat-up time prepares water to ideal temperatures in under 2-hours 
• Wood-burning heater constructed of 304 stainless steel 
• Polished stainless steel chimney with protection 
• Durable Thermo-Spruce tub surround (1.65” thick), painted black  
• Superior thermal resistance (R-value) to retain heat  
• Matching Thermo-Spruce wood steps for easy access 
• Extra thick steel reinforced foam cover, folds for ease of removal and storage 
• Dark grey marine grade vinyl cover exterior 
• Integrated hot tub drainage tap 
• Up to 6 bathers 
• Exterior dimensions – 79" diameter and 37” high  
• Interior dimensions – 71" diameter and 33” deep 
• Designed by SaunaLife and handcrafted in Northern Europe 

 

 

Thermo-Spruce Material Advantages 

 

 

• Lasts up to 2X longer than Cedar 
• Superior thermal resistance (R-value) 
• Eco-friendly 
• Ideal for water use (stable)  

 

 

Includes:

 

 

 

Model S4B Outdoor Wood-Burning Hot Tub  

 

 

• Fully assembled hot tub 
• Steps 
• Insulated cover  
• Drainage with tap 
• Polished stainless steel chimney 
• Chimney cap 

 

 

 

Interior Dimensions	71" Diameter x 33"D
Exterior Dimensons	79" Diameter x 37"H
Water Capacity	304 Gallons
Product Weight when filled	3064 lbs
Stove Dimensions	19.8"L x 11.8"W x 13.1"H
Chimney Dimensions	95"H x 4.7" Diameter

Shipping Dimensions	91"L x 46"W x 87"H
Shipping Weight	595 lbs

 

 

 

 

 

A True Wood-Fired Soaking Experience

 

 

Unlike electric or gas hot tubs, the S4B returns to the roots of bathing—where heat is natural, intentional, and immersive.

 

 

• High-efficiency stainless steel wood-burning heater with dual heat chambers

• Rapid heat-up time, bringing water to ideal soaking temperatures in under two hours

• No electricity required, making it ideal for off-grid living and eco-minded homes

• Even, consistent heat that surrounds the body naturally

 

 

This is soaking as ritual—slow, grounding, and deeply satisfying.

 

 

 

Designed for Comfort & Shared Relaxation

 

 

Every detail of the S4B is designed to support long, comfortable soaks with friends or family.

 

 

• Spacious interior accommodates up to six people comfortably

• Thick, dark grey contoured fiberglass lining supports relaxed posture

• Smooth, easy-to-clean surface enhances comfort and durability

• 71” interior diameter allows freedom of movement without crowding

 

 

Whether enjoyed solo under the stars or shared with loved ones, the experience feels generous and unhurried.

 

 

 

Built with Premium, Outdoor-Ready Materials

 

 

The S4B is crafted from Thermo-Spruce, a thermally modified wood engineered for water exposure and outdoor durability.

 

 

• Lasts up to 2X longer than Cedar

• 1.65” thick Thermo-Spruce tub surround, painted black for a refined, modern look

• Superior thermal resistance (R-value) helps retain heat longer

• Naturally stable, eco-friendly, and ideal for wet environments

 

 

This construction ensures the tub performs beautifully across seasons and climates.

 

 

 

High-Performance Stainless Steel Heating System

 

 

At the heart of the S4B is a robust 304 stainless steel wood-burning heater, designed for efficiency and longevity.

 

 

• Dual heat compartments maximize heat transfer

• Resistant to corrosion and extreme temperatures

• Polished stainless steel chimney ensures proper draft and safe operation

• Protective chimney cap included

 

 

The system delivers powerful, reliable heat with minimal effort.

 

 

 

Arrives Fully Assembled — Ready to Enjoy

 

 

The S4B is delivered fully assembled, eliminating complex installation and allowing you to begin soaking sooner.

 

 

Included features:

 

• Matching Thermo-Spruce wood steps for easy access

• Extra-thick insulated steel-reinforced foam cover, foldable for storage

• Marine-grade dark grey vinyl cover exterior

• Integrated drainage tap for easy water management

 

Everything is thoughtfully included for a seamless ownership experience.

 

 

 

Elegant, Functional Design for Outdoor Living

 

 

With its deep black exterior, natural wood accents, and sculptural form, the S4B complements a wide range of outdoor environments, from modern backyards to rustic cabins and remote retreats. It feels intentional, grounded, and timeless.

 

 

 

Northern European Craftsmanship, Naturally Heated Wellness

 

 

Designed by SaunaLife and handcrafted in Northern Europe, where wood-fired bathing is a long-standing tradition, the S4B reflects generations of expertise in materials, thermal performance, and outdoor wellness design.

 

 

The result is a luxury wood-burning hot tub that invites you to slow down, warm up, and reconnect, without plugs, panels, or distractions.

 

 

Soak deeply. Heat naturally. Live the SaunaLife.