
Why this wood, and why cleft. Everything behind a roof covering that lasts a hundred years.
“Cleft wood sheds water. Sawn wood drinks it.”

Cleaving follows the natural grain of the wood and leaves the fibres intact, so water runs off. Sawing severs them, and water soaks in. That is the whole difference between a roof that ages and a roof that rots.
Each 33 cm bolt is quarter-cleft, then stripped of its sapwood. Only the durable heartwood goes onto a roof.
The fibres stay intact: water runs along the grain and never penetrates the wood.
Growth rings sit perpendicular to the faces: no swelling, no distortion over time.
Sweet chestnut regrows in 20 years. Managed coppice, no quarrying, no extraction.
Does not break in transport, in frost or in storms. No replacements to plan for.
Rich in tannins, it stands up to rain, frost, sun and insects, with no treatment at all.
Wood conducts neither heat nor cold: a natural thermal regulator on any roof.
Rich in tannins, sweet chestnut is rated durability class 2 under EN 350: it resists fungi and insects without the slightest treatment. Properly laid and ventilated, it lasts beyond a hundred years.

Freshly laid, sweet chestnut shows warm tones, from honey to golden brown. Under sun and rain it turns, within months, to a deep silver grey, losing none of its qualities.
That patina is not a flaw: it is the mark of time on a noble material, the same grey you admire on hundred-year-old roofs.
Compliance & commitments
Recognised as a heritage material by the Architectes des Bâtiments de France, the French heritage authority. Technical documentation available for your files.
Receive a sample of hand-cleft chestnut, or the full technical data sheet for your project file.