Are all types of wood suitable for the Shou Sugi Ban technique?

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Is any type of wood suitable for Shou Sugi Ban? This is a crucial question to consider before choosing timber for a façade, a fence, a decking area or a decorative interior finish. Fire alone is not enough to achieve a durable and attractive result. What also matters is the type of wood, its density, stability, moisture content, the pattern of its growth rings, and the way it will subsequently be brushed and oiled. A well-chosen material brings out a rich texture, increases the surface’s durability and produces a result that harmonises with the character of the project.

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Are all timber species suitable for Shou Sugi Ban? Key principles for choosing a species

Not all timber species react in the same way to fire. Species that are too soft, unstable, damp or of poor quality may brown unevenly, split or lose the desired effect after brushing. In this charring method, what matters is the predictability of the material: the timber must withstand high temperatures well, retain its structure and allow for control over colour and texture. In practice, stable, well-dried timber species that are suited to the installation site yield good results. The requirements differ depending on whether the timber is intended for a façade, a fence or a decorative interior finish.

Why does the type of wood determine the result of the charring process?

Charring does not mask the quality of the material; on the contrary, it brings it fully to the fore. Growth rings, knots, heartwood, sapwood and natural variations in colour become more visible when exposed to fire. It is precisely for this reason that timber intended for this technique must be chosen with care. Shou Sugi Ban effectively highlights the depth of the grain, but requires the boards to be properly prepared. The intended use of the material is important: a plank installed outdoors must be more resistant to damp, sunlight and temperature fluctuations; indoors, on the other hand, the colour, texture and appearance of the finish are often more important.

‘Thermally Treated Pine’: a stable timber produced through heat treatment

Thermally Treated Pine is pine that has been subjected to high temperatures under controlled conditions. The material thus gains dimensional stability, exhibits reduced moisture absorption and takes on a darker, more refined colour. Once charred, it offers a understated, modern look that blends well with fences, façades and garden architectural features. Its advantage lies in its predictable behaviour under varying conditions, provided the boards are correctly installed and protected. It is a good choice when the balance between aesthetics, durability and the natural character of the surface is paramount.

Siberian larch, Scandinavian spruce and Douglas fir: three different effects after charring

Siberian larch is denser and more weather-resistant than many common conifer species. After flame treatment, it can develop a pronounced, deep grain, making it an ideal material for cladding and fencing. Scandinavian spruce is lighter in weight and colour; once flame-treated, it produces a more uniform and soothing effect. Douglas fir is characterised by a pronounced grain and a warm colour that deepens after flame treatment. Each of these species reacts differently to the flame; the choice should therefore depend on the desired appearance and the conditions of use.

Accoya, a modified timber for demanding applications

Accoya is a modified timber, valued for its high stability, durability and resistance to moisture. Thanks to its modified structure, it warps significantly less than many traditional timber species, making it an ideal choice for outdoor projects. Once charred, it develops an elegant and distinctive surface, whilst retaining predictable dimensional stability. It is a good solution for façades, decking, windbreaks and architectural features, where weather resistance and the aesthetic appeal of a natural, well-finished surface are important. However, it requires appropriate preparation, installation and maintenance.

How should you choose timber for charring?

Randomly selected boards may have excessively high moisture content, an irregular structure, internal stresses, defects or inconsistent quality. Once charred, these imperfections often become more visible. Charred wood boards require proper drying, selection and treatment, as the flame strongly emphasises the wood’s character. The subsequent stages, including brushing and the application of a finishing oil, also play a vital role. Shou Sugi Ban timber can vary in the degree to which it has been charred, brushed and protected; therefore, before making your choice, it is important to determine whether the boards will be exposed to intense sunlight, rainfall, contact with the ground or frequent temperature changes. When assessing the material, attention should be paid to:

  • the dimensional stability of the timber species in question;
  • the level of natural resistance to moisture;
  • the visibility of the growth rings after charring and brushing;
  • the intended use: cladding, fencing, decking, interior or decorative feature;
  • the possibility of regular oil treatment;
  • the quality of the drying process and the selection of the planks.

It is only the combination of these factors that ensures a surface which will look its best once installed and retain its character throughout the seasons.

Summary

Are all types of timber suitable for Shou Sugi Ban? Not all of them, if the aim is a durable, uniform and aesthetically pleasing result. The most suitable types are those that are dimensionally stable, well-seasoned and suited to the installation site. Pine, larch, spruce and Douglas fir, as well as modified woods, can be used to achieve a variety of visual and functional effects. The choice should depend on the intended use of the boards: on a façade, a fence, a decking area or indoors. The final result depends not only on the fire, but also on the quality of the material, the burning method, the brushing, the protection and correct installation – all of which are handled by Atelier TwentyOne.