Big, bold and rugged thermo-spruce decking

Thermory’s Kodiak decking range can be used to create a particularly rugged and natural atmosphere. Its sturdy boards, with their brushed texture, are inspired by the majestic Kodiak brown bear and represent the harsh, wild charm of the Alaskan forests, its natural habitat.

The Kodiak range is made with spruce that has been thermally modified using only heat and steam. Modified right through to the core, the boards are dimensionally stable and offer rot resistance for at least 25 years if correctly installed. Kodiak spruce decking boards provide a natural and rustic feel alongside the first-class qualities that come with thermally modified wood.

Application: Decking
Species: Thermally modified spruce
Modification level: Intense
Use: Exterior
Durability class: 1 (25+ years’ protection against wood decay)
Finish: Unoiled
Texture: Brushed
Installation types: Visible, hidden
Installation methods: Screws, clips

Highly durable and comfortable decking with beautiful knotst



A clean, stylish look with easy installation

Thermory wood distinctive_knots


Showcasing the natural beauty of pinewood

Thermory brushed wood


Highlights the wood’s natural grain



Thermally modified wood is more durable with a lower moisture content

Thermory cladding durability


Thermory’s thermo-ash cladding has the highest available durability class



Wood sourced from sustainable forests with chemical-free modification


Why choose Kodiak thermo-spruce decking?

If you prefer rustic, natural-looking wood but you need premium durability, Thermory Kodiak thermo-spruce is the perfect material for your deck.

Extra-wide boards ensure fast installation with fewer seams, creating a stylish and modern look and feel.

The brushed top surface accentuates the natural appeal of the wood grain.

Unlike other softwood decking, Kodiak spruce boards show no visible sapwood thanks to the thermal modification process – just the consistent color of heartwood throughout.

Because they are so stable, we recommend installing Kodiak boards with PC clips.

Thermal modification gives spruce the highest durability rating (class 1, 25+ years) so your terrace will look great for decades.

Our thermo-spruce is environmentally friendly, as the thermal modification process is chemical free and no harmful waste is generated.

We offer thermally modified spruce with the Nordic Swan Ecolabel, which certifies that the wood originates from responsibly managed forests, is free of chemicals and is extremely durable when used outdoors.

Read more about thermal modification

Additional options for easy installation and a flawless finish



An attractive finish with no visible screws



Reduces waste, saves expenses

Thermory easy installation


Ingeniously simple fixing methods


Spruce produces less resin

Norway spruce (Picea abies) is a coniferous tree of the pine family in the genus Picea, that is widespread in Europe.

Without any treatment, spruce wood is lightweight, soft and almost white in color with medium mechanical properties. Spruce splits more easily than pine but it is less resinous. The wood is very well suited for thermal modification, which makes it significantly more durable and stable while also giving it a beautiful golden-brown tone.


The color of the wood changes over time

Thermal modification gives spruce wood a beautiful golden-brown tone.

As with any wood, the surface of thermally modified spruce will fade to a natural silver-gray color over time. This process starts immediately after the products are installed and can take a few months to several years depending on how much UV light they are exposed to. The durability of the boards is not affected. If you would like to preserve the darker tone of thermally modified wood, we recommend oiling the boards once a year using a UV-resistant oil.

Deck maintenance. To oil or not to oil?

Thermally modified decking boards do not necessarily require surface treatment, but regular maintenance and oiling will refresh the appearance of your deck and make it easier to clean.

We recommend cleaning and maintaining the deck before the start of the summer season.

Lightly sanding faded boards will remove the silvery surface colour and restore the wood’s original appearance.

If you would like to preserve or change the tone of thermally modified wood, apply UV-resistant oil to the boards once a year.

If you would like to preserve the tone of boards that have turned grey over time, use colourless oil without a UV filter on the boards.

The oil should be applied only to clean, level, dust-free surfaces.

Download decking maintenance guide

Recommendations for installing Kodiak thermo-spruce decking

To make your deck last as long as possible, it’s extremely important to use the correct installation techniques.

We recommend using thermally modified ash or spruce joists with durability class 1 for the substructure. This way, the substructure will last as long as the decking.

When installing thermo-spruce decking, make sure that the heartwood side of the boards is face down.

Choose the PC clip fixing for a deck surface without any visible screw holes or screws.

By choosing decking boards with end-matching, you can minimize time, material costs and labor when installing boards of different lengths. The load-bearing capacity of the end-matched part of the decking is verified, and the two boards don’t necessarily need to meet directly over a joist.

Apply end wax to all the ends of the every decking boards before prior to installation to ensure a longer service life.

Follow the decking installation guide for correct installation.

Download decking installation guide

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