Kaarna (Bark)
Kaarna reflects the warm brown hues of a rugged surface. The shade evokes the heart of the forest and the beauty of nature.
Applications
Manufacturing
Kaarna product is made by charring the wood surface at over 1000 °C using Hiil's charring technology. After charring, the product is pressure-washed, brushed, dried and oiled with clear special linseed oil. The oil adds protection and binds the char so that it does not dust or flake off.
Specifications
| Surface | Charred, washed, brushed, 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 B-class when treated with fire retardant, spruce as material. |
.lFQ4VqIV_20ixcx.svg)
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 Kaarna
AITO Saunas’ charred wood cladding
AITO Sauna builds saunas where Finnish design meets everyday wellbeing. Hiil has supplied charred wood surfaces to AITO projects in Ibiza and beyond.
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.
Charred roof terrace
Design studio Amerikka’s new office roof terrace with Kaarna decking – charred, brushed, and oiled surface.