Lexicon DIY-Knowledge


Lärche / Larix decidua



The larch is commonly found in Europe, Asia and North America. Originally it grew exclusively in Alpine regions, but since the 16th century the precious wood was cultivated in lower regions, too. Hereby it was used as a pioneer plant: the decomposition of the needles it shed in autumn quickly led to an improvement in the soil condition (nitrogen cycle), which in turn made it possible to cultivate more demanding species like the spruce. With a height of up to 50 meters and a trunk diameter of up to 1.5 meters this coniferous tree can become up to 600 to 800 years old. Larch trees prefer climates with lots of light, warm summers, cold winters, dry atmosphere and no fog. They have very little resistance against polluted air. Therefore they don?t grow well in cities and urban areas.

When young, this slim, cone-shaped tree develops a smooth yellowish bark which turns into a grey-brown, up to 10 cm thick scaly bark with deep fissures. The trunk consists of a thin yellow layer of sapwood and the precious red-brown heartwood. This wood is of medium hardness, tough, with straight fibres and a characteristic annual ring structure. Larch darkens strongly under the influence of light. Due to its high resin content, the heartwood is much more durable then the sapwood.
The different larch timbers resemble each-other in pattern, colour and technical properties. This decorative, pore-less needle wood can be easily processed, split (pre-drilling before screwing is recommended) and glued. As special feature we should mention the acid resistance of this type of wood. The formation of a surface film after varnishing with polyester-based varnish and its lastingness can be a problem (over pitch pockets). There is also a problem with cement bonding, and the wood tends to turn grey-blue when in simultaneous contact with iron and water.
The heartwood of the larch tree is weather-proof, and therefore preferred as structural timber for outdoor constructions, for bridges and in mining. Window frames, railway sleepers, posts, stakes, garage doors, floors, masts are made of larch wood. It is also used for interior fittings and furniture. Larch is industrially processed into boards and veneers. The sapwood can be included in this due to the decorative effect.