About Siberian larch

As the name suggests, the Siberian larch originates from Siberia in Russia. Specifically called the Siberian Taiga. Larch is the most common tree species in Russia that has gigantic forests.

On the Siberian Taiga, growth conditions are quite unique. Summer is short, and winter is long and cold. This means that the trees are very slow-growing and thus have very dense annual growth rings. The larch trees are therefore also very dimensionally stable.

Frøslev only supplies certified Siberian larch from sustainable forestry. 

The Siberian larch is used for terrace boards, façade cladding and also for our system fences. Note that all Siberian larch posts are laminated.

Characteristics

As mentioned, the slow growth results in narrow annual growth rings with a distance between the growth rings of only between 0.5-1 mm. In addition, there is a clear difference between heartwood and sapwood, and the proportion of heartwood can often be more than 90%. Heartwood is durable in itself, and Siberian larch wood has therefore often been used as a substitute for pressure-impregnated wood.

The larch is levorotatory throughout the growth period unlike spruce and pine which are levorotatory first and then dextrorotary. This means that larch is twisting more which places greater demands on the fixing. 

The knots are blackish brown, and resin pockets may appear in the wood.

Processing and protection

Due to the large proportion of heartwood, larch has a greater durability than pine and spruce, however, without achieving the same durability as pressure-impregnated pine. This is especially pronounced where the wood is in direct contact with soil or brick/concrete. In these areas, it is necessary to use pressure-impregnated wood to obtain acceptable durability.

Larch can be pressure-impregnated, and this should always be done if the wood will be in direct contact with soil or brick/concrete. However, the pressure impregnation is only in the outer sapwood, and the protective effect is therefore limited. 

To the greatest extent possible, all wood must be protected by 'structural protection' which means that you plan and build in such a way that the wood is ventilated and water is drained off so that the tree can dry out.

Wood is a natural material and will eventually turn grey. It is a good idea to protect the wood with suitable wood preservatives when dry - either with flat paint finish or transparent wood preservatives. Note that the Siberian larch is difficult to treat with water-based tree preservatives.