Short answer: Yakisugi is a traditional Japanese finish created using the Shou Sugi Ban technique which chars the surface of sugi to create a durable, low-gloss, textured finish. Correctly specified and detailed, it delivers a stable, weather-resistant cladding with striking shadow and grain.
Why architects choose yakisugi
- Beauty: Unique, bold, finely detailed – loved by craftsman and homeowners who dare to be different
- Material honesty: it’s timber, finished by fire—not paint or film-build and no nasty chemicals
- Texture & depth: the char accentuates grain and creates rich, graphic facades.
- Weathering performance: the carbonised layer acts as a sacrificial surface.
- Maintenance logic: no brittle coatings to crack; touch-ups are simple.
- Sustainability story: efficient use of slow-grown sugi, long service life when detailed well.
Quick note on terms: In Japan the species traditionally used is Cryptomeria japonica (sugi). “Shou sugi ban” is a Westernised term; we use yakisugi and sugi throughout.
How yakisugi is made (process overview)
- Selection: Profile, grain & grade selected for intended use.
- Charring: Through our specialist charring partner Chartek [www,chartek.co.nz] we ensure the traditional process of yakisugi is applied to each board.
- Brushing (optional): brushes remove friable soot, revealing pattern and setting the textured finish.
- Oiling/Sealing: penetrating char oil stabilises the surface and mitigates rub-off. Alternatively, our brushed finishes can come in a range of earth pigmented natural oils. Our preferred natural oil finish partner is the Natural House Company [https://www.naturalhouse.co.nz/]
- Grading & QA: boards are checked for consistency in char, moisture, and dimension.
Pentarch New Zealand supplies boards that are charred, optionally brushed, and factory-oiled, ready to install. See our [Profiles & Finishes] and [Spec Pack v1] for details.
Traditional shou sugi ban method: three sugi boards are tied together and the interior surfaces are charred through the stack effect in the resulting tunnel.
Finish options (what to specify)
We offer three straightforward finish families so specifiers can balance look vs. upkeep.
1) Full Char (Yakisugi)
- Look: cracked “dragon skin” texture, deep black.
- Touch: soft; minimal brushing to keep the scale intact.
- Where it shines: shaded elevations, sculptural facades.
- Maintenance: spot oiling as required; periodic re-oil as required or at least every eight years
2) Refined Char (Ebonii)
- Look: matte black, grain visible, smoother hand.
- Touch: brushed once to reduce soot transfer.
- Where it shines: mixed light, urban sites, interiors (feature walls).
- Maintenance: predictable re-oil cycle; easy long-term care.
3) Brushed & Toned (Wabi Sabi)
- Look: grain-forward, from smoky brown to near-black tones.
- Touch: smooth to the hand; least rub-off risk.
- Where it shines: coastal and high-exposure sites; family homes.
- Maintenance: predictable re-oil cycle; easy long-term care.
Tip: If the client wants “black” with the least upkeep, specify a brushed Ebonii + pigmented penetrating oil rather than a fragile full-gloss film.
Profiles, dimensions, and fixing
- Common profiles: vertical & horizontal shiplaps, horizontal bevel back, rainscreen boards over battens, TG&V. Custom profiles available on enquiry
- Thickness/widths: typically profiles are ex a 150-200 x 25-50mm board. Custom sizing available on enquiry
- Ends & edges: end-seal freshly cut ends with oil supplied; maintain char continuity at corners (mitre, cover board, or metal angle, flashings over the top of end grain).
- Fixings: stainless steel/silicon bronze nails & screws with colour-matched heads; secret-fix options available dependent on profile. We recommend a rose head for that extra feature.
- See our [Profiles & Finishes] and [Spec Pack v1] for details.
Performance notes (plain-English)
- Weathering: the char is a sacrificial surface. As it erodes, the underlying timber remains protected; scheduled oiling slows that erosion.
- “Will the char rub off?” Some transfer is normal on freshly charred surfaces. Brushed + factory-oiled boards minimise this; a light first clean after install helps.
- Movement: cedar is dimensionally stable, but all timber moves.
- Fire behaviour: yakisugi is not fireproof. The char layer can slow surface flame spread compared to raw timber, but compliance must be addressed project-by-project. If fire performance is critical, talk to us about available test data and alternative assemblies.
- Mould & staining: design for drainage and drying (drips, drip-edges, cap flashings). Keep landscaping irrigation off cladding. Most surface moulds occur from a build up of dirt, decaying plant matter and pollens. Mitigation is easy through an annual house wash which also serves as an easy timber re-oil check. If the water doesn’t bead on the surface it indicates the need for a top-up of oil.
Maintenance schedule (guideline)
Real-world cycles depend on exposure, site, and colour choice. Start with this:
- At install: gentle wash-down to remove loose soot; oil touch-ups to cut ends and penetrations.
- 6–12 months: first condition check (especially north/west faces).
- Every 18–24 months (coastal 12–18): light clean + assess. Re-oil high-exposure faces if water no longer beads.
- After extreme weather events: brief inspection of fixings, flashings, and base details.
Cleaning: Low-pressure wash to surface. Avoid harsh detergents; use a neutral pH cleaner if needed. No water-blasters.
Common myths—cleared up
- “Char = paint.” False. Char is a carbon layer fused to timber fibers; it isn’t a film.
- “It flakes like stain.” Incorrect. There’s no brittle film to peel; the char abrades gradually.
- “All yakisugi looks the same.” Not true. Char pattern is determined by the underlying timber. Char depth, brushing, and oil pigmentation create distinct aesthetics and maintenance profiles. It’s not “yakisugi” unless it’s sugi. All other charred timber species are “yakitimber”
Sustainability & provenance (the short version)
Sugi is slow-growing in Japan and well-suited to yakisugi. Charring is energy-efficient compared with many film finishes, and maintenance relies on penetrating oils rather than heavy recoating. Responsible forestry and durable detailing lengthen the service life of the cladding—good for both carbon and cost over time. Read more in: [From Forest to Facade: Responsible Timber & the yakisugi Lifecycle].
FAQs
Q: Can I use yakisugi inside?
A: Yes. We recommend brushed + sealed finishes for interiors to prevent transfer; confirm fire and acoustic requirements per project.
Q: What about colour fade?
A: All exterior timber finishes change over time. Darker, more heavily charred finishes hold depth longer; pigmented oils stabilise tone.
Q: Lead times?
A: Typical lead times are 4-12 weeks depending on profile and finish. Contact us early for large runs or special profiles. We recommend contacting us once your plans are at full working drawings. This enables stock to be set aside and inclusion into our finish production schedules for a timely site delivery.
Next steps
- Order a free sample kit to compare finishes in your project light. [Order Samples →]
- Download the Spec Pack v1 with profiles, fixing notes, and junction diagrams. [Download →]
- Talk to our technical team for project-specific advice or fire performance queries. [Book a 15-minute consult →]