Redwood Outdoors Thermowood Indoor Sauna 4 Person Indoor Sauna

Every Redwood Outdoors Indoor Sauna kit comes complete with a Harvia electric heater, wooden heater guard, water bucket & ladle, sauna rocks, and interior seating benches. Our saunas will heat up to 195 F in under an hour, and can be enjoyed either wet or dry, catering to a true Scandinavian sauna experience.

Thermowood Construction 

Thermowood is created by heat treating Scandinavian softwood to temperatures ranging from 180 – 230° in special chamber kilns for up to 96 hours. Steam is used as a protective gas and helps to prevent the wood from splitting and becoming damaged during treatment.

Learn more about Thermowood in our FAQ section!

Thermowood’s Characteristics & Qualities

This process causes chemical and structural changes to occur within the timber, which therefore alters some of its characteristics and qualities. Some of the characteristics and qualities that make Thermowood such a popular specie includes:

Dimensionally Stable – The intensive heat the wood is exposed to during its production dries out deep into the core, causing all moisture and resin to be removed from the timber. Thermowood therefore doesn’t react to changes in humidity as drastically as untreated wood (the risk of swelling, cracking and shrinkage is decreased), allowing it to retain its shape far better. The wood also doesn’t secrete sap or resin even in high temperatures.

Environmentally Friendly – The softwood used to produce Thermowood originates from well-managed, PEFC-certified forests, and as no chemicals or foreign substances are involved during its production, Thermowood is an environmentally friendly material produced by using only natural methods.

Resistance to Rot and Fungi – Due to the heating process breaking down hemicellulose, the wood doesn’t contain the appropriate nutrients to allow rot and fungi to grow and develop.

Increased Longevity – When wood is treated with heat, its average life span is prolonged meaning your sauna will last a lifetime!

Improved Insulation – Wood that has been heat treated is much more porous than untreated wood, vastly improving its insulating properties.

Traditional Scandinavian Design

This Scandinavian indoor sauna has a classic beauty in its elegant simplicity. Our indoor saunas are constructed with durable Thermowood lumber that fit together forming a strong exterior. Not only are our indoor saunas lovely to look at, their design is incredibly energy efficient and helps to distribute the heat evenly throughout the interior.

Harvia Sauna Heater, Made In Finland
Harvia is the world’s leading sauna heater manufacturer and Harvia heaters are considered the industry gold-standard. Harvia is was established in Finland in 1950 and has built an international reputation for exceptional quality. With a Harvia heater, you know you are getting a reliable product that you and your family can trust. All our Harvia sauna heaters are ETL certified and are manufactured in Finland.

Manual Control Or Wi-Fi Control Heater Options
Our manual control heaters have two dials: a temperature dial and a timer. The timer can be set for up to an 8-hour delay, meaning you set your heater to come on while you are out and your sauna will be ready when you get home.

Our digital Wi-Fi heaters can be controlled via the digital wall pad mounted nearby your sauna, or from any smartphone or tablet. The big convenience of the Wi-Fi control is the remote start capability which allows you to pre-heat your sauna from anywhere—whether at the office or on the slopes. With few taps on your phone, your sauna will be ready when you get home. Wi-Fi heaters can also be pre-set to come on at a specific time of day, such as early in the morning.

Unfortunately, you cannot upgrade a manual control heater to a digital Wi-Fi system in the future. While the manual and digital heaters look very similar, they are in fact totally different heaters. This means you must select the control system you are going with at the outset.

Easy Self Assembly
Putting together the our sauna kits is easy! All our saunas are designed with the DIY customer in mind. All the pieces are pre-cut and grooved, so no sawing or cutting is required.

Anyone with novice woodworking skills could build one in approximately 4 hours. All the assembler will need is a level, Phillips screwdriver, 7/16″ and 9/16″ open end wrenches, 9/16″ deep socket wrench, vise grips, and a mallet.