What are the special features of larch as a material?
Abbreviation DIN EN 13556: LADC
Botanical name: Larix decidua (European larch)
Distribution: Europe, temperate climate zones
Trade names: (European) larch (GB); meleze (FR); larice (IT); lariks (NL); alerce de Europa (ES)
Short description
Until the discussion on tropical timber in the early 1990s, the domestic larch played only a minor role for the German timber industry. Its importance, especially for gardening and landscaping, has increased considerably since then. Since the small amount of timber in Germany (only about 3% of the forest area) cannot meet the increasing demand, it is supplemented by imports of the high-quality Siberian larch (L. gmelinii, L. sibirica).
The sapwood is pale reddish and narrow, clearly separated in colour from the yellowish to reddish to orange-brown heartwood, strongly darkening in light; due to the regular alternation between light-coloured early wood and the sharply defined darker late wood with distinct grain (tangential surfaces) or stripes (radial surfaces). The small resin channels are only visible on smooth cross-sections with a magnifying glass. Fresh wood has a slightly resinous odor.
Overall character
Straight grained, decorative softwood with a narrow sapwood, clear core colouring and a pronounced annual ring structure.
Deviations
In European larch, coarse, knotty wood from fast-growing cultures; twisted growth and deforestation. Siberian larch wood is generally very dense, of a rather yellowish-brown colour and predominantly knot-free.
Surface treatment
Larch wood is to be treated well after removal of any resin spots with any means and by any method, covering or glazing. Because of its beautiful colour and structure, colourless or slightly pigmented glaze coatings are preferred, which bring out the full beauty of the wood.
Workability
Larch belongs to the harder coniferous woods. The processing of both fresh and dry wood can be carried out quickly and gently by machine and hand with all tools. It is also good for peeling and for knives, as long as the number and size of the branches is small. Pre-drilling should be done for strong nails and screws.
Drying
Stamina is satisfactory to good. Both natural and technical drying proceeds rapidly with a greater tendency to cracking and deformation. Bonding is problem-free.
Natural durability (DIN-EN 350-2)
Natural durability: The wood of the European larch is moderately to slightly durable, whereas that of the Siberian larch is durable to moderately durable and is preferable for outdoor use. Resin-rich qualities are highly resistant to acids.
Areas of application
Versatile construction timber for medium loads for interior and exterior use
Exterior applications, mainly in gardening and landscaping; window and door frames (usually made of glued edging); floors (planks, solid wood and ready-to-lay parquet); furniture, panelling, interior doors; stave wood for chemical containers and vats.
Remarks
The wood contains water-soluble, washable ingredients. In damp wood, ferrous metals can cause discoloration of the wood, corrosion of the fasteners is possible.
Larch - Technical properties
Weight fresh750-800 kg/m³
Bulk density air-dry (12-15% u)0.47-0.62 g/cm³
Compressive strength u12-1545-62 N/mm²
Flexural strength u12-1588-100 N/mm²
Modulus of elasticity (bending) u12-1510600-14500 N/mm²
Hardness (JANKA) ⊥, converted3.8-5.7 kN
Hardness (BRINELL) ⊥ to fiber u12-1519-25 N/mm²
Differential shrinkage (radial)0.14-0.18
Differential shrinkage (tangential)0.28-0.36 %
pH value4.2-5.4
Natural durability (DIN-EN 350-2)2-4