Larch wood. Materials for playground equipment, part 1

21. September 2018

As a CO2-neutral and resource-saving raw material, larch is perfectly suitable for playground constructions and impresses with its natural durability. Read everything you need to know about larch wood in our fact sheet.

Table of content

Larch wood – a fact sheet

  • Botanical name: Larix decidua Miller
  • Family: Pine family (Pinaceae)
  • Range: Europe, Asia, North America, but originally only in the Alps, Tatra, Carpathians
  • Sex: unisexual
  • Pollination: wind pollination
  • Needles / leaves: about 3 cm long needles
  • Fruits: small, light brown cones, female as well as male
  • Growth: conical, tends to twisting growth
  • Roots: heart-shaped, branched, up to 2 m deep
  • Flowering time: March – May
  • Maximum tree height: 10 – 40 m
  • Maximum age: up to 500 years
  • Bark: very scaly, grey to reddish brown
  • Preferred habitat: bright, cool, loamy soil
  • Frost hardiness: -32 °C to -36 °C
  • Larch species: Siberian, European, Japanese and West American
  • Tree of the Year: Germany 2012 and Austria 2002
  • Likes: does not like air pollution
  • Fun Facts: poorly flammable, pioneer tree, likes neither late nor early frost

Diseases and pests of larch wood

The following diseases and pests can sometimes become a problem for larch wood:

  • Fungal infections (falling sickness caused by Rhizoctonia solani, grey mould rot caused by Botryotinia fuckeliana, larch chute caused by Mycosphaerella laricina and larch canker caused by Lachnellula willkommii).
  • Insect pests (small and large larch leaf wasp, larch blister moth, larch grey moth, larch leaf miner, larch leaf wasp, nun moth or Lymantria monacha, longhorned beetle and bark beetle)
  • Stem and root damaging fungi (white and brown rot, root rot and Hallimasch)
  • Browsing by mice and game
  • Exposure to smoke causes needle necrosis (yellowing, burns and death of the needles)

The properties of larch wood

The reason why larch is so well suited for playground equipment is that it has several outstanding properties:

  • highly resistant
  • very resinous
  • reddish colour
  • dries quickly
  • low shrinkage
  • high durability
  • excellent construction timber
  • weather resistant
  • good alternative to tropical wood
  • very dimensionally stable
  • good environmental balance

Technical data of European larch

  • Weight: 590 kg/m³
  • Bulk density air-dry (12-15% u): 0.47-0.62 g/cm³
  • Compressive strength approx. at 46 – 58 N/mm²
  • Flexural strength approx. 90 – 99 N/mm²
  • Modulus of elasticity: approx. 12,000 N/mm²
  • Natural durability (DIN-EN 350-2) 3 – 4

International designations of larch according to DIN EN 13 556

The larch has many faces. You can read below which names the larch bears:

  • European larch LADC
  • American larch LAOC
  • Japanese larch LAKM
  • Siberian larch LAGM
  • Dark field larch LAER

Is the larch a deciduous tree or a conifer?

The larch is a coniferous tree. And it is also the only European tree that sheds its “foliage” or needles in winter and is thus winter bare.

Why does the larch shed its needles?

It is assumed that larches shed their needles in order to survive better. Initially, the larch is only found at high altitudes. In high altitude regions, extremely low temperatures and strong frosts prevail in winter. However, the tree evaporates water through its leaves or needles. This is not possible during frost – without the needles. However, the larch can withstand sub-zero temperatures down to approx. -37 °C.

Larch wood and Venetian turpentine

Moreover, the most valuable turpentine can be extracted from bored larch trunks: larch turpentine or Venetian turpentine. It has a very typical, slightly citrus-like smell, similar to turpentine oil, and is thick, yellowish-brown and sticky. It is primarily extracted in Styria, Carinthia and Tyrol. Venetian turpentine serves as a high-quality painting medium.

How does the larch grow?

Even before the needles sprout, the flowering time of the larch begins in spring. The larch flowers have a very pleasant fragrance. In autumn, they also produce cones. Shortly afterwards, the needles sprout from the shoots in clusters, fragrant and fresh green. The seeds are in the cones, which often only germinate the year after they have grown. The cones themselves, on the other hand, remain on the tree – often for many years after dispersal. Larches typically grow very straight, but in mountainous regions, they often show twisting growth and curvatures.

Use of larch for eibe play equipment

For some of our playground equipment, we use larch glulam. The surface of our glulam is treated with a transparent wood oil certified according to DIN EN 71-3. This not only brings out the natural grain but also the typical warm colour of the larch wood species. Dimensional stability is ensured by the waterproof glueing according to DIN EN 14080 of individual boards to form a large cross-section. This means that warping, cracking, or the like is avoided. The larch wood used is low in sapwood. Furthermore, fine-grained larch with a high raw density from sustainably managed forests guarantees a long service life and enjoyment of the play equipment.

Further important information on eibe play equipment made of larch wood

  • Hazard class: 3 – no direct contact with the ground
  • Durability class: untreated 3
  • Protection against insects/bugs, fungi and sunlight: Impregnated (oils)
  • Hygroscopicity: no cores in the outer lamellas

For more information: Robinia is another type of wood that is particularly suitable as a material for outdoor playground structures. Because it is incredibly resistant! You can read more about the wood species Robinia here.

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