Hiili (Carbon)
Hiili is the bold, black classic of the Hiil range. Shaped by fire, its deeply textured grain symbolises transformation and resilience.
Applications
Manufacturing
Hiili product is made by charring the wood surface at over 1000 °C using Hiil’s charring technology. After charring, the product is quenched with water, dried and oiled with clear special linseed oil. The oil binds the char on the surface so that it does not dust or flake off.
Specifications
| Surface | Charred, oiled |
|---|---|
| Wood species | Pine, Kiertopuu® pine |
| Wood certification | PEFC certified |
| Planed thickness | 22, 28, 45 mm Note! Charring reduces the thickness of the wood piece by 0-3 millimetres and rounds the edges. |
| Width | 120, 145, 170, 195 mm |
| Panel overlap | -12 mm from width |
| Profiles |   |
| Country of origin | Finland |
| CE marking | Product is CE marked |
| Fire class | D class C-class indicative. B-class with fire retardant indicative. |
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Weather exposure
Weather exposure test for Hiil Oy charred wood products
Natural Resources Institute Finland - 27 March 2025 results - Veikko Möttönen and Nina Pottonen.
Weather exposure test programme: 102 min UV exposure and 18 min UV+rain exposure, repeated over 6 weeks (1008 h). Equivalence: The treatment can be considered to correspond to approximately 3 years of outdoor exposure to rain and sunlight. UV radiation dose in the test was approximately 218 MJ/m².
Downloads
Find more on the Resources page.
Example projects using Hiili
Halo Igloos Resort – Northern lights and charred wood
Halo Igloos is a glass igloo resort in Rovaniemi where Hiil Kiertopuu products bring an ecological dimension both outdoors and indoors.
Sauna Panels and Roof in Charred Wood
A private home sauna with charred wood wall panels and ceiling in Hiili finish. Backrest from the same board material for durability.
Charred exterior cladding for a detached house carport
Charred wood cladding on a carport in a detached house setting – Finnish Hiili and Kiertopuu® in a clear architectural frame.
Charred exterior cladding on archipelago rock
A detached house on archipelago shoreline – charred exterior cladding and oiled Hiili make the building a calm part of the landscape.
Kuusijärvi saunas – exterior cladding and decks in charred wood
Public smoke saunas and service buildings at Kuusijärvi – charred cladding and Noki decks connect the new to an old ritual.
Saunalautta Hiisi – Charred walls inside and out
Saunalautta Hiisi by the sea – charred wood on the exterior and inside. Necto Design Oy; Hiili stands up to sea wind and sauna moisture.
Charred exterior cladding for Tikkurila fire station
Tikkurila readiness station in Vantaa – a building by P&R Arkkitehdit with Hiili exterior cladding. A calm, recognisable expression.
TRIB3 Helsinki Sture, charred wood building the atmosphere
TRIB3 Sture boutique fitness studio with charred wood – Hiili and Korppi at reception, Kuura in the Pilates room. A shared, community-led atmosphere and a clear material language.
Charred exterior cladding for a wind farm visitor centre
Pahkakoski wind farm maintenance and visitor centre in Yli-Ii – light stone wood and charred wood create a recognisable facade.