Finishes

Shou Sugi Ban

Timber burned on purpose. The Japanese technique gives a deep, textured black that is UV-stable and asks almost nothing of you afterwards — and it comes in two versions that behave nothing like each other.

What it is

Fire as a finish.

The charred face. Deep, textured black that is UV-stable and remarkably low maintenance — charred in-house, ready in two weeks like everything else.

The surface is burned until a carbon layer forms, then either left as it falls or brushed back to reveal the grain underneath. What you end up with depends entirely on which of those two you choose — and they are not two shades of the same thing. One is protected by the char. The other is protected by oil.

It is done here, on our own line at Pomathorn Farm, and it ships in about two weeks like everything else we make.

Charred and brushed — the grain pulled back out of the char.

The choice that matters

Two faces, two entirely different lives.

Everything else about a charred board is a detail. This is the decision: whether the black is carbon, or whether the black is oil over carbon. It sets what the wall looks like in fifteen years and what you have to do in the meantime.

Deep Char

Grain
No visible grain — alligator char
Over time
The carbon layer is the UV protection. Stays black for decades; the odd char flake is cosmetic.
Care
None the timber needs — re-oil only if you want it jet black forever
Holds well — holding its original colour

Charred & Brushed

Grain
Grain revealed through the char
Over time
The oil, not the char, carries the colour — left alone it weathers like any stained board.
Care
Re-oil every 3–10 years to hold the colour; optional if silvering suits
Sheds colour early — holding its original colour

Ageing and care intervals fact-checked 2026‑07‑29 against Nakamoto Forestry and shousugiban.co.uk documentation. Realistic UK exterior-cladding intervals, not marketing ones — south- and west-facing walls sit at the short end.

Variants

And then what goes on top.

The char is the surface. What is applied over it is a second choice — leave it black, lift it towards grey, or put colour on it.

Deep Char

Charred & Brushed Smooth

Oyster

Painted

Two stock colours — or any RAL to order

Painted charred boards carry the same two stock RAL colours as any other painted order, and any other RAL is mixed to order — the picker on any species page carries the code through to the quote. Coated charred orders ship with a tub of touch-up paint, same as the rest.

Which charred options a given timber is priced for is shown on its own species page. See the seven timbers →

Living with it

Almost nothing — but the almost matters.

Cleaning

Warm water and a soft cloth or brush. No chemicals, no abrasives, and never a jet wash — the char is a surface layer and pressure takes it off.

Damage and cut ends

Cut ends and knocks get a matching touch-up treatment. Never try to re-burn or char a board on site. Anything that breaks through the charred surface — a ladder, a nail gun, rough handling — wants a maintenance coat promptly, so water cannot get behind it and lift the char locally.

Flakes are normal

A few platelets or a little crackle coming away from a deep-char face is the material behaving correctly. It is not a defect and it is not a reason to call us.

Honest limits

What charring does not do.

Charred timber gets sold with claims attached to it. These are the ones that do not hold up, and we would rather you heard them from us than found out on a project.

It does not make the timber last longer

Charring is a decorative, sacrificial surface treatment. It does not upgrade the board's durability class. A charred larch board is still larch underneath — choose the species for how long it has to last, and the char for how it looks.

It does not improve fire performance — and it can worsen it

This is the one that surprises people. Testing to the EU classification method found that brushing after charring drops fire performance below that of untreated timber for fire growth rate, and that every charred variant raised smoke development. So charring is not fire-neutral, and it is certainly not a fire upgrade.

A fire rating comes only from a tested fire treatment. Ours is Fire Treated to Euroclass B, which is a different product applied on the coating line — and it is chosen in the price calculator, not here. If a project needs a Euroclass figure, email us and we will give you a tested classification rather than a number off a webpage.

Sources: TDCA and Timber Development UK guidance on charred timber; Buksans et al. (2021), cone calorimeter ISO 5660‑1 with SBI EN 13823. Verified 2026‑07‑30 and approved by the Tiny Temple team 2026‑07‑31.

Hold a charred board before you commit to a wall of them.

Samples are free. Ask for deep char and charred-and-brushed together — side by side in daylight is the only way the difference lands.

Order free samples Price a charred spec → All four finishes →