Shorea laevis

Shorea laevis (syn.: Hopea laevifolia Parijs, Shorea laevifolia Endertplatz, Shorea rogersiana Raizada & Smithinand ) is a flowering plant in the family wing of the fruit family ( Dipterocarpaceae ). It comes in Southeast Asia before the primary rainforest.

The trade name for the wood are Yellow Balau Balau and not unique or bangkirai; under the trade name bangkirai the woods Red Balau, Keruing, Seraya and White Merawan are sold, for example. The wood is hard and durable, which is why Shorea laevis is also grown outside their natural range and traded internationally.

Features

Shorea laevis grows as a tree reaching a height of up to 75 meters and a diameter at breast height of about 1.5 meters. The alternate arranged leaves are undivided, glabrous and shiny. The stipules are about 8 millimeters long.

The approximately 5 millimeters long yellowish- green flowers are borne in paniculate inflorescences. The approximately 10 mm long nut fruits have about 30 millimeters long wings, with which they are spread by the wind.

Wood

The heartwood appears when fresh yellowish brown to greenish, it often darkens to olive brown after. The core is not always distinct from the lighter sapwood. However, the color varies greatly. The growth ring boundaries are not pronounced, dry wood without characteristic odor. The color and structurally predominantly homogeneous wood is a medium to coarse texture and high density ( 0.7 to 0.9 g / cm ³).

Occurrence

The natural range of Shorea laevis includes Myanmar, Thailand, Malay Peninsula, Sumatra and Borneo. The trees grow in undisturbed primary forest at altitudes of about 600 meters on sandy or clayey soils. They prefer slopes and hill crests, but come on alluvial ago. Shorea laevis is cultivated outside their natural range in India, Pakistan, Sri Lanka, Laos, Vietnam, Cambodia and the Philippines.

Use

The Yellow Balau wood is heavy and very well weather- resistant; it dries slowly and tends thereby to surface cracks. It has high strength values ​​which are higher than 50% oak; therefore it is difficult to work with. The density is 20 to 40% higher than that of the oak. When planing, it may come to be torn because of the interlocked growth. The heartwood is very resistant to fungi and insects. Yellow Balau is one of the most durable woods, even under tropical conditions, it is permanent. The classification of the natural durability against wood- destroying fungi according to EN 350-2 takes place in class 2 ( durable). The life expectancy under temperate climate conditions is 15 to 25 years.

The wood is used for all types of buildings, especially in outdoor areas such as the Bridge and water, usually without any impregnation. In India it is used primarily as railway sleepers, used in Malaysia as utility poles, mining timber and shipbuilding, in Europe and elsewhere as construction wood for the dock and harbor, moorings, piles, patio coverings and outdoor furniture.

Some trade names are: Yellow Balau, Sal ( India), Balau ( Sarawak ), bangkirai (Indonesia), Selangan Batu ( Sabah ), Tang, Teng and Chan ( Thailand), Gisok or Yakal (Philippines). Balau and Selangan Batu ie Malay terms. Do not confuse it with the actual Sal ( Shorea robusta).

The wood is rarely available with FSC certification. An origin from overexploitation can not be excluded.

About Your Yellow Balau Wood

Very rarely occur resin pockets on ( narrow gaps that are filled with white crystals ).

Cracking: To keep in storage the fine cracking especially on the sides of the head as low as possible, they are often painted at the factory with wax. One must, therefore, re-cut the boards during installation.

Light surface cracks ( they can occur by weathering ) have no static effects.

Greying: Like any other type of wood, as well as graying bangkirai. To obtain the initial color, the surface oil can be (see Wood preservatives ).

Ingredients in bangkirai react with galvanized metals. They form black spots. You can avoid this if you use stainless steel screws.

Bleeding: When using bangkirai outdoors it could leak out of ingredients. Surrounding materials should be protected by film, for example. The balcony area you should pay particular attention to the emergence of the ingredients. ( Pollution of the facade possible)

Swell

• Description of Shorea laevis at the National Herbarium of the Netherlands (English )
• Martin Chudnoff: Tropical Timbers of the World. United States Department of Agriculture, Forest Service, Handbook 607, 1984.
• The great book of wood. Nikol, Hamburg 2003, ISBN 3-933203-69-4, p 256