What are the special features of beech as a material?
Abbreviation according to DIN EN 13556: FASY
Botanical name: Fagus sylvatica, family Fagaceae - Fagoideae
Distribution: Europe, Mediterranean area including North Africa and Middle East, temperate Asia
Trade names: beech, copper beech, common beech (D), beech (USA, GB), hêtre (F), faggio (I), beuken (NL), haya (E), kaym (TR), rödbok (S), buk (CS, PL, RU), bökk (H)
Beech - Description and characteristics
Short description
Beech is the most important deciduous tree species in Germany, accounting for about 15 % of the forest area. Newer silvicultural concepts, which take into account the characteristics of beech as an excellent mixed tree species, lead us to expect an increasing amount of beech wood in the future. The highest added value currently lies in the upper strength classes of the trunk wood, whose natural accompaniment is the red heartwood of beech. This facultative core, induced by external factors (especially branch breakage), develops under very individual conditions in the physiologically active tissue that beech possesses over the entire cross-section of the trunk until old age. The simple light beech is still preferred by the market at present, but thanks to targeted marketing, the demand for beech redheart is increasing, especially in the furniture and parquet sectors.
Beech trees prefer to grow in the plains to lower altitudes of the low mountain ranges and require good soils. the trees reach heights of 25 to a maximum of 40 m with knotless shafts of up to 15 m and diameters of 50-80 cm, occasionally up to 1 m and more. The trunk, which grows in the stand, is mostly straight-edged, cylindrical and woody.
Colour and structure
The sapwood is grey-pink to yellowish and takes up the entire cross-section of the trunk. At the age (from approx. 80 years on) it mostly comes to the formation of a facultative redheart. This is characterized by a lively, multi-zone or cloudy gradated red-brown colouring. Growth zones are clearly recognizable by denser late wood with fewer vessels and form fine grain on the tangential surfaces. Wood rays are present in two different sizes and produce characteristic dark spindles on the tangential surfaces, which are visible as clear mirrors on the radial surfaces.
Overall character
Bright, homogeneously plain wood with a hard and dense surface characterized by characteristic wood rays. The wood of older trees often has a decorative red-brown colour core (red heartwood).
Surface treatment
The dry wood can be treated with all preparations according to any method, if the preparations are one that is adapted to the evenly dense surface. flowability or concentration. Beech wood can be adapted to almost any desired colour by staining. Where the natural colour or the colour intensified by steaming is to be expressed, clear and matt glossy agents are generally used for surface treatment, such as colourless glazes, matting, clear waxes, natural oils (e.g. linseed oil) or transparent varnishes.
Machinability
All wood assortments of beech can be easily and cleanly processed, due to the generally homogeneous structure and despite the high hardness. Exceptions to this are qualities with coarse fibre deviations, e.g. due to knots. Screwing and nailing requires pre-drilling. Beech is well suited for the production of sliced and rotary cut veneers. In order to maintain the respective colour characteristics, the use of UV-stable surface treatment agents is recommended. Beech is easy to bend after steaming. The sapwood area can be saturated very well, but the redheart is difficult to saturate.
Drying
The strongly shrinking beech tends to warp and crack when drying. Stacking and drying should therefore be carried out with great care to avoid discoloration which would impair quality. Drying of the red-heart wood must also be carried out carefully due to the slower release of moisture.
Natural durability (DIN-EN 350-2)
The natural durability of beech, including the red heartwood, is poor in accordance with durability class 5 of DIN EN 350, as the core materials are not incrusted into the cell walls.
Areas of application
Due to the very good strength properties, the high hardness and the simple wood appearance of the non-cored beech, it is in demand for the uniform furniture and door industry as well as for stairs, floors and rotary cut veneers for plywood. The unique colouring of the red heartwood beech predestines it for the production of decorative furniture and interior furnishings with sophisticated design. Due to its low natural durability, either classic wood protection methods (e.g. sleeper wood) or new, innovative wood modification methods (e.g. thermal beech) are used for exterior applications.
Remarks
Red core formation must not be confused with quality-reducing wood discoloration reactions, such as the splash core or discoloration after felling (running-in, stick).
Beech - Technical properties
Weight fresh: 820-1 070-1 270 kg/m³
Density air-dry: (12-15% u)0.54-0.72-0.91 g/cm³
Compressive strength u12-1535-53-99 N/mm²
Flexural strength u12-1563-105-210 N/mm²
Modulus of elasticity (bending) u12-1510 000-16 000-18 000 N/mm²
Hardness (JANKA) ⊥, converted4,97-7,10 kN
Hardness (BRINELL) ⊥ to fiber u12-1528-40 N/mm²
Differential shrinkage (radial)0.19-0.22 %
Differential shrinkage (tangential)0.38-0.44 %
pH value5.1-5.4
Natural durability (DIN-EN 350-2)Class 5