About European larch
As the name indicates, this variant originates from Europe. The European larch is not to be confused with the Siberian larch as it differs in many areas and most importantly in durability properties.
The European larch grows in the southern part of Central Europe (the Alps, the southwestern part of Poland, southern Germany). It is also found elsewhere in Europe, but rarely in quantities that justify actual forestry. In these areas, it is logged with other forests and rarely separated from other production.
We only use certified European larch
Characteristics
The European larch is characterised by being almost pure heartwood and with small knots. Boards of European larch often contain some knots, and if there are many, the strength of the wood is weakened. Boards seem relatively heavy compared to pine and spruce which results in a very durable look.
The wood can vary widely in colour from dark yellowish to reddish brown depending on the habitat and age. There is a clear division of heartwood and sapwood, and the separation is a few cm within the bark with a large colour difference. The width of the annual growth rings varies greatly depending on the growth rate and habitat but differs from the Siberian larch by having wider annual growth rings and a marked difference between spring wood and late wood.
The proportion of heartwood can be relatively large, and the heartwood is relatively durable and is comparable to pine heartwood.
The European larch is levorotatory for the entire growth season as opposed to spruce and pine which are initially levorotatory and then dextrorotary.
This causes the larch to twist, placing greater demands on the fixing - there must be less distance between fixing points (max. 40 cm), and drilling should be done to prevent cracking.
Nails and screws should also be at least 2½ times the wood dimension and always of stainless steel. As the European larch is acidic, surface-protected steel will be attacked/corrode quickly, and black streaks will appear on the wood in connection with moisture.
The European larch is used as structural timber and for façade cladding.
Processing and protection
Larch is a little more difficult to process due to a large number of knots and because the wood is harder and more brittle than spruce and pine.
Larch can be pressure-impregnated according to the NTR standards. If the wood is to be used in direct contact with soil or brickwork, pressure impregnation should always be done to avoid attack by rot and fungi.
Larch is quickly attacked by mildew etc. and should therefore be treated as soon as possible.
The first treatments should not involve water-based systems due to the acidity of the tree, however, acidity decreases over time, and later treatment can therefore be done as requested (ask the tree preservative supplier/producer).
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. Treatment also extends the life of the wood.