A Complete Guide to Sauna Wood Protection

One of the most common questions we receive at Ice Cold Spice is whether an outdoor sauna needs to be painted or treated before it can be used.

The answer is that it depends on the manufacturer, the type of timber and the finish you choose. Many premium outdoor saunas already arrive with a high-quality factory-applied protective coating, while others are intentionally supplied untreated so the owner can select a finish that suits their property and preferred level of maintenance.

Neither approach is right or wrong. What matters is understanding why timber protection is important and choosing the most appropriate solution for your sauna.

Why Does an Outdoor Sauna Need Protection?

A sauna is exposed to much harsher conditions than many other garden buildings.

Over the course of a year, the timber experiences rainfall, ultraviolet (UV) light, frost, changing humidity and repeated heating and cooling cycles as the sauna is used. Although quality sauna timber is designed to withstand these conditions, all natural wood gradually weathers if left completely unprotected.

Without an exterior protective coating, timber may:

• Fade as it is exposed to sunlight.
• Develop small surface cracks as moisture levels change.
• Weather to a silver-grey appearance.
• Absorb more moisture during prolonged wet weather.
• Require more frequent maintenance over its lifetime.

These changes are largely cosmetic rather than structural, but applying a suitable wood protection system helps preserve the appearance of the sauna while reducing the effects of long-term weather exposure.

Why Aren't All Saunas Factory Treated?

Many buyers assume every premium sauna should arrive fully painted or stained.

In reality, there are several reasons why some manufacturers intentionally leave the timber untreated.

Firstly, colour is highly personal. Some homeowners prefer the natural appearance of untreated spruce or thermowood, while others want contemporary graphite grey, black or darker timber finishes that complement modern architecture.

Secondly, some customers prefer to apply a locally sourced treatment after installation or choose a coating system based on their property's specific environment.

Finally, natural timber varies in grain and colour. Applying a finish after installation allows owners complete control over the final appearance.

That said, many of the premium sauna manufacturers we work with already offer professionally applied factory finishes, allowing customers to receive a sauna that is protected from day one without any additional work.

Paint, Stain or Oil: What's the Difference?

Not all timber protection products perform the same job.

Wood Stains

Exterior wood stains are the most popular option for outdoor saunas.

Rather than forming a thick coating on the surface, quality stains penetrate into the timber while allowing it to breathe naturally. They provide excellent protection against moisture and UV exposure while still allowing the natural grain of the wood to remain visible.

For most outdoor saunas, a high-quality stain offers the best balance between durability, appearance and ease of maintenance.

Exterior Paint

Paint provides a completely opaque finish that hides the natural timber beneath.

It offers excellent weather protection and is often chosen for contemporary homes where black or dark grey finishes complement modern architectural styles. However, repainting usually requires more preparation than maintaining a stained finish.

Wood Oils

Natural oils enhance the appearance of the timber while helping repel water.

Although they can produce a beautiful natural finish, they generally require more frequent reapplication than professional exterior stains and are therefore less commonly used on large outdoor sauna cabins.

Does the Timber Affect the Final Colour?

Yes.

The same stain can produce noticeably different results depending on the timber species.

Spruce

Spruce is naturally light in colour with a subtle grain pattern. It accepts stains exceptionally well, making it suitable for both traditional and contemporary colour schemes.

Thermowood

Thermowood has been heat-treated to improve its dimensional stability and resistance to moisture. It naturally has a deeper brown tone than spruce, meaning every stain appears richer and darker once applied.

Because wood is a natural material, every sauna is unique. Small variations in grain, colour and texture should be expected and are part of the character of real timber.

Factory-Applied Protection

Many of the premium outdoor saunas available from Ice Cold Spice can be supplied with factory-applied protective finishes.

One of the leading systems used by several European manufacturers is Remmers, a specialist timber protection range developed specifically for exterior wood structures.

Factory application offers several advantages:

• Professional, even coverage.
• Consistent colour across the entire sauna.
• Protection from UV exposure and moisture from the day the sauna is installed.
• Reduced maintenance during the early years of ownership.
• A high-quality finish applied under controlled factory conditions.

For many homeowners, factory finishing provides peace of mind while ensuring the sauna looks its best from the moment it arrives.

Popular Remmers Colour Options

Depending on the manufacturer and sauna model, a range of factory-applied finishes may be available.

Some of the most popular include:

Chestnut – A warm, natural finish that enhances the grain of the timber while creating a timeless appearance.

Palisander – A rich dark brown stain suited to premium outdoor living spaces.

Graphite Grey – One of the fastest-growing choices for contemporary homes, pairing beautifully with large glazed panels and modern landscaping.

Black – A striking architectural finish that creates a bold contrast against gardens while complementing modern homes and outdoor kitchens.

The appearance of every finish will vary slightly depending on whether it is applied to spruce or thermowood.

How Often Does a Sauna Need Retreating?

Even factory-protected saunas benefit from periodic maintenance.

The exact interval depends on several factors, including:

• How exposed the sauna is to sunlight.
• Local weather conditions.
• Coastal or inland locations.
• The type of finish applied.
• The timber species.

As a general rule, the exterior should be inspected annually. If signs of fading or weathering begin to appear, applying a fresh maintenance coat will help preserve both the appearance and long-term durability of the timber.

Which Option Is Right for You?

There is no single answer.

If your chosen sauna is available with a factory-applied protective finish, it is often the simplest solution. The timber arrives professionally treated and ready to withstand the elements from installation.

If your preferred sauna is supplied untreated, that shouldn't be viewed as a disadvantage. It simply provides greater flexibility to choose the colour and protection system that best suits your home and landscaping.

At Ice Cold Spice, many of our premium outdoor saunas are already available with factory-applied wood protection, while others can be customised after installation. If you're unsure which option is right for your property, our team can advise on the most suitable treatment, maintenance schedule and finish for your chosen sauna and location.

Final Thoughts

A high-quality outdoor sauna is a long-term investment, and protecting the timber is one of the simplest ways to preserve both its appearance and performance.

Whether you choose a factory-finished model or apply a protective coating after installation, quality wood protection helps reduce weathering, maintain the natural beauty of the timber and extend the life of your sauna.

At Ice Cold Spice, we carefully select premium European sauna manufacturers that use high-quality timbers and professional finishing systems. Many of our saunas can be supplied with factory-applied protection, and where this isn't available, we're always happy to advise on the most appropriate products and maintenance to keep your sauna looking its best for many years to come.