SUMI 炭
Deep charred. Raw intensity. The purest expression of Yakisugi.
SUMI refers to the purest and most traditional form of Yakisugi, characterized by a dark, jet-black finish created through the carbonization process of Japanese cedar wood. This ancient technique not only enhances the wood’s aesthetic appeal but also increases its resistance to rot, insects, and fire.
Exterior
Interior
Facades
Feature Walls
Interior
Facades
Feature Walls
Coating3X Polyurethane
FinishCharred – deep carbonization all four sides at 1700C+
Moisture ContentKiln-dried KD 14% (+/-4%)
SpeciesCryptomeria Japonica – native to Japan. Known as “Sugi” in Japanese.
OriginGifu Prefecture, Japan – 100% Made in Japan
Decay Resistance+72% vs. untreated spruce/pine (VTT Finland Research)
Moisture Absorption92% reduction vs. untreated wood (Kyoto University)
Expected Lifespan80-100+ years with proper installation
Interior – Uchi
Paneling, feature walls, millwork
10mm x 135mm x 1970mm
10mm x 135mm x 2940mm
10mm x 135mm x 3940mm
10mm x 135mm x 2940mm
10mm x 135mm x 3940mm
Exterior – Soto
Facades, cladding, siding
18mm x 165mm x 1970mm
18mm x 165mm x 2940mm
18mm x 165mm x 3940mm
18mm x 165mm x 2940mm
18mm x 165mm x 3940mm
- Each board is unique – slight variations in pattern and depth are natural and expected.
- Handle with care during installation. Wear gloves and protect adjacent surfaces.
- Suitable for both interior and exterior applications.
- Fire resistance is enhanced – longer ignition delay and reduced flame spread vs. untreated wood.
- Natural silver-gray patina develops over time when exposed to UV.
- Minimal maintenance – no painting, staining, or chemical treatment needed.
- For exterior use, install as rain screen with adequate ventilation gap.
- Coat all field cuts and rips with touch-up oil or matching stain.
Substrate – Interior
Stud wall, fire-rated drywall or plywood. Tongue & groove to studs or furring strips.
Substrate – Exterior
Rigid furring max 16″ (400mm) on center. Rain screen system with minimum 19mm ventilation gap.
Fastening – Interior
23 gauge pin nailer recommended. Nail length = board thickness x 3.
Fastening – Exterior
Stainless steel face nails or screws – two per furring strip. Pre-drilling recommended.
Clip System
Recommended for high-end interior installations. Clips and nails provided upon request.
Layout & Profiles
Vertical or horizontal orientation. Shiplap and square edge profiles available. Stagger joints minimum 24″.