There is a European standard that defines durability of wood and how to test, classify wood and wood products according their natural durability to biological agents.
The European standard EN 350 evaluates and lists the durability properties of all types of wood. The standard applies to solid wood and only heartwood 100%. Sapwood is never durable for any species. This is very important to know and it is also equal important how much or the wood is sapwood and heartwood. Some species is made up of only heartwood and some is only sapwood. This will make a huge impact on the durability of the woodproduct in use.
The durability is stated on a scale from 1 to 5 where 1 is very durable and 5 is non-durable. Furthermore, there is information on variability and how much of it normally consists of heartwood and sapwood, respectively.
Wood spies type |
Durability class |
Type of wood |
| Larch (origin Europe and Japan) | 4 | Conifers |
| Pine (European origin) (sylvestris) | 3-4 | Conifers |
| Douglas fir (native to North America) | 3 | Conifers |
| Douglas fir (grown in Europe) | 3-4 | Conifers |
| Yew (origin Europe) | 2 | Broadleaf |
| Birch (origin Europe) | 5 | Broadleaf |
| Ash (origin Europe) | 5 | Broadleaf |
| Oak (origin Europe) | 2-4 | Broadleaf |
| Teak (origin Asia) | 1 | Broadleaf |
| Teak (grown Asia etc.) | 1-3 | Broadleaf |
When intervals are stated, such as on Pine and on Oak, it means that there are large deviations depending on, for example, plant location etc.
The standard is available for purchase from where standards is published and sold.
