Castanea sativa
A lighter, softer cousin of oak. Tannin-rich heartwood gives it real durability outdoors, but those same tannins react with iron — so fixings need to be stainless or brass.


Tree
Native across southern and Mediterranean Europe, with long-managed coppice woodlands in France, Italy, and the Iberian peninsula. Also grown in the UK and parts of central Europe. KORENA sources mainly from European coppice and standard-tree harvests.
Wood appearance
Straight-grained and coarse-textured, with prominent ring-porous figure that reads as oak at a glance. Heartwood is a warm honey-brown that ambers with age; sapwood is a narrow pale band. Lacks oak's strong medullary rays, so quartersawn faces are calmer and less flecked.

Mechanical properties
| Density (kg/m³) | 540–650 kg/m³ |
|---|---|
| Janka hardness (N) | 2,700–3,300 N |
| MOR: modulus of rupture (MPa) | 70–85 MPa |
| MOE: modulus of elasticity (GPa) | 8.0–10.0 GPa |
| Radial shrinkage | 3.5–4.5 % |
| Tangential shrinkage | 6.0–7.5 % |
| Volumetric shrinkage | 12.0–13.5 % |
| Natural durability (EN 350) | Class 2 — Durable |
Working with it
1 = difficult · 5 = excellent
Saws and planes well with sharp tooling. Softer than oak, so it dents more easily but is also kinder on edges. Splits readily when screwed near ends or edges — pre-drill and countersink. Glues and steam-bends predictably. Turning is workable but the coarse grain can tear on end-grain cuts.
Drying
Dries slowly and is prone to ring shake and honeycomb if pushed. Air-dry to around 25–30% MC before kilning, then run a gentle schedule. Movement in service is moderate — tangential shrinkage near 7% means wide boards want room to move in panels and tabletops.
Finishing
Takes oil, hardwax, and water-based finishes cleanly. Open pores benefit from a grain filler if you want a glass-flat surface, or leave them open for a tactile, oak-like read. Fuming with ammonia darkens it deeply thanks to the high tannin content. Test stains on offcuts — tannins can pull cool tones grey.
Durability and safety
Dust is a reported skin and respiratory sensitiser — extract at source and wear a fitted mask when sanding or routing. Heartwood is rated food-contact safe once finished. Critical detail: chestnut tannins react with iron and produce black staining wherever the two meet in the presence of moisture. Use stainless steel or brass fixings, and keep iron tooling off damp stock.
Best uses
Pairs and substitutes
Often substituted for
Sourcing and sustainability
Native European species, IUCN Least Concern, no CITES restrictions. Much of the European supply comes from coppice systems — short-rotation, low-input, and a working part of rural land management in France and Italy. Ask for FSC or PEFC chain-of-custody where it matters to your client. KORENA records the certification it holds on the slab passport.
Buyer questions
Sweet Chestnut is best matched to projects such as External cladding and rainscreens, Interior wall and ceiling panelling, Barn-style and rustic furniture frames, Garden furniture and pergolas, Coopered tanks, vats, and planters, Beams and exposed structural framing, Doors, gates, and shutters, Flooring in lower-traffic rooms. The final choice should consider grain, finish, movement allowance, and the room where the piece will live.
The listed Janka value is 3,010 N and the density is 590 kg/m³. Use these as comparison signals, not as a guarantee of how a finished surface will wear.
Check measured length, width stations, thickness, drying method, moisture notes, colour variation, defects, and origin. Compare the measured outline against the finished drawing before reserving the slab.
Current stock
We email you when fresh Sweet Chestnut slabs land at KORENA. Each piece is one of one, so early notice matters.
Sources