Larch

Other name:    European Larch

Botanic name: Larix decidua

German:          Lärche

Culture history

Sunlight enhances the friendly character of the larches. Its fresh light-green in spring and its warm red-golden in October create a bright landscape. In the Engadin for example the large larch-woods are the result of calculated selection – because of tourism, too. For hundreds of years larch wood has been used at houses in higher regions as a long-lasting shelter against weather. It varies from red-golden-brown to blackbrown on the sunny side and silver-gray at the weather-face. The legend that the wood is incombustible is first mentioned in the paper of the Roman architect Vitruv, who had known the tree and the wood only by hearsay. Buti t kept told until the late Middle Ages. There is to distinguish between the fine wood of the Stone-larch and the coarse one of the grass-larch which grows in deeper regions and is less durable.

In general

The larch is a typical mountain tree and a mixed-forest tree. Its strong bark protects it even from light falling rocks. It is frost-resistant but it isn’t situated for regions with late frost. About 7 percent of the Austrian commercial timberland are larches. It can become more than 800 years old but as a commercial timber it is felled after 100 to 140 years.

Characteristics of the timber

It´s light sapwood is very small and the colour of the heartwood varies from light-brown to intensively red-brown. It darkens very much. The contrast between early-wood and late-wood within the annual ring is highly marked. About ½ to 1/3 of the annual ring is late-wood. It´s fine resin canals are especially found in late-wood.

Properties

Larch-Wood shows very good strength property but it depends on the location (kiln densitiy 400 to 820 kg/m³). It is medium-hard (Brinell hardness 19 N/mm²). There are no difficulties in seasoning larch-wood. It is also easy to work but concerning the surface treatment it is to say that sometimes it may be necessary to pretreat it with resin solvents. Because of the hard branch-wood and the irregular fibre course there is the risk of splintering. It is also recommended to prebore because of the splintering. Concerning the resistance against fungal infestation the larch is found in class 3 to 4 which means moderate to little moderate in resistance. Its treatability in the heart is very bad and in the sapwood it is moderate.

Use

Larch-wood is used outdoors and indoors, bearing and non-bearing. It is used for highly loaded structural designs and for boats, bridges, earthworks and water engineering. Indoors it is used for windows, doors, floors, panelling and furniture. In recent times outdoor panelling has become very popular because it can be kept untreated.

Quelle: www.proholz.at