Quality with a luxurious look


Atibt: Subdivided into Light Oak and Heavy Oak.
Other names: Belgian, German, French, native, Polish, Romanian, Slavonian, Spessart oak, depending on its origin (Netherlands), chêne (France), Eiche (Germany), oak (Great Britain).
Botanical name: Quercus petraea (Mattuschka) Lieblein (= Q. sessiliflora Salisb.), Q. petraea (Mattuschka) Lieblein (= Q. sessiliflora Salisb.). robur L. (= Q. pedunculata Ehrh.).
Family: Fagaceae.
Growth area: Europe and Asia Minor.
Tree description: Height 18-30 m, maximum 45 m. The straight branch-free trunk is up to 15 m long and has a diameter of 1.2-1.8 m. The oak tree can reach a high age (400 years).
Supply: Sawn timber and veneer, unedged timber and veneer as well as finished products.

About the durability of European light oak and heavy oak: pedunculate oak is considered less durable than sessile oak. The currently mentioned durability is class 2-3. Experience shows that the origin of oak influences its durability. Oak from the Baltic Sea region is said to be more durable than oak grown further south.

- Pedunculate oak (Quercus petraea) according to NPR 5493, quality class European, is classified in strength class C24.

- Central European oak (Quercus robur & Quercus petraea), quality class A/B in accordance with NEN 5477,
  is classified in strength class C20.

Oak heartwood has a yellow-brown to dark-brown colour and is clearly distinguishable from the 25-50 mm wide pale-brown sapwood. Quarter sawn wood has characteristic shiny "mirrors", caused by the wide radii. The wood has ring pores, which gives rise to flame markings on the face of the wood. Structure and quality vary depending on the growing conditions. Slavonian oak, for example, grows slowly and evenly, has a straight grain and an even tone and is soft and easy to work with. Oak from Poland is tougher and harder and Dutch oak is usually coarser. Flawless Slavonian Oak is often delivered in varying widths up to a maximum length of approx. 240 cm, because only the rootstock of the tree does not contain any branches and therefore no knots are visible and the wood has almost no defects. 

It is possible to use finely sawn structural grade parts indoors for furniture etc., but bear in mind that they have a robust appearance (knots, hairline cracks, water stains) and should be left to acclimatise for a sufficiently long time (at least 3 weeks, at a humidity level of 18%) in a medium-dry room (such as the garage) before being assembled in the dry living room. Oak has a high tannin content, so metals in contact with oak corrode quickly.

Type of wood: Hardwood
Wire: Straight
Nerf: Moderately coarse to coarse.
Voluminous mass: (500-)670- 710-760(-970) kg/m3 at 12% moisture content, fresh 900-1200 kg/m3.
Work Medium (VM ± 640 kg/m3. Large (VM ± 725 kg/m3.
  Drying: very slowly. Some tendency to cracking, deformation, collapsing and discolouration is present, especially in the first drying periods. We recommend applying a sealant to end-grain wood in order to avoid end-grain cracks. However, oak can be dried very well if the necessary precautions are taken.
Machinability: Its machinability is strongly dependent on its density. In general, however, oak is easily machined, turned and milled, both by machine and by hand. When planing oak, a reduced chip angle is recommended to achieve a smooth surface. Oak, once dried to the required degree of dryness, works moderately well. However, it is always preferable to use quarter-sawn timber for special purposes (for doors, floors and windows).
Nailing and screwing: Moderate. Pre-drilling is recommended. Stainless steel fasteners are recommended, otherwise blue-black discolouration occurs in contact with iron and light brown in contact with copper or brass.
Adhesives: Good
Bending: Very good
Surface finish: Good. When using (clear) water-based finishes, the high tannic acid content should be taken into account.
Sustainability Fungi 2. Anobium G. Termites M. The sapwood is susceptible to attack by Lyctus.
Strength class: In a limited test in 2000, Polish oak was classified in strength class K24 according to NEN 5498:1997. The visual grading criteria for Polish Oak concern the proportion of brush not exceeding 0.3 and the thread pitch not exceeding 1:10. For the other permissible imperfections in the application categories, see the Dutch practice guideline NPR 5493; 1999, Quality guidelines for hardwood in hydraulic engineering works. It is expected that with a larger number of tests with Polish oak, or the expansion of the growth area, a higher strength class classification will be feasible.
Impregnability: Heartwood 4. Sapwood 1.
Details: Wet wood is corrosive in contact with iron. Blue-black discolouration is the result of the reaction between iron and the tannic acid (tannin) in the wood. Oak in contact with cement or concrete will slow down the curing process. The American Oak grown in the Netherlands, which is marketed as domestic American Oak, comes from Quercus rubra Du Roy (see American Red Oak). Turkey oak, chêne chevelu or zerreiche, Quercus cerris, southern Europe and south-west Asia, resembles European oak in its wood properties. It sometimes has a reddish tint. Volumic mass between (710-)770(-870) kg/m3. Works large. Dries very slowly, whereby crack formation and deformation can hardly be avoided. Can be worked like American red oak. Bends very well. Durability against mould 3, termites M. The sapwood is susceptible to attack by Lyctus and Hesperophanes. Impregnability of the heartwood 4, sapwood 1. The applications are limited by the poor drying properties and the high shrinkage during drying. Possibly applicable for heavy constructions and small flawless wood for bending and cutting of heavy selected logs. Japanese Oak, Quercus mongolica Fisch. ex Turcz. var. grosseserrata (Bl.) Rehd. et Wils. and Quercus spec. div., is yellow-brown to grey-brown in colour with little gloss and can therefore be distinguished from European oak species. In general, Japanese Oak is softer, looser and lighter in structure. Japanese oak usually has many more growth rings per 10 mm than any other type of oak and is therefore suitable for use as bending wood. Japanese oak shrinks more than the other oak species and the so-called mirror, which is especially sought after for panels, is not very noticeable. It is mainly used as bending wood for chair hulls. Further as other oak species, except for construction and outdoor work. Japanese oak is, in contrast to the past, only little imported.
Applications: It is not possible to list all the possible uses of oak. The wood can be used in almost every industry and almost everywhere, as construction timber, in shipyards, in bridge building and water works, as well as in the chemical industry, the furniture, toy, sports equipment, bodywork and agricultural machinery industries. Also for frames, windows, doors, parquet and strip floors, plywood and veneer, fenders, bridge decks, chutes, railings, wagon and ship floors, church furniture and tools. The native oak is especially used for construction wood (repair of old buildings), window frames, beams, industrial floors, ladder rungs (ash is better), ship's keels and skins, sleepers, fenders, bridge decks, poles, lock gates, dolphins, shore protection, etc. European oak is irreplaceable in the manufacture of casks for wine, sherry, cognac and other alcoholic beverages, which derive much of their flavour from the tannins present in oak.
Quality requirements: European oak is mentioned in the Dutch practice guideline NPR5493:1999, Quality guidelines for hardwood in hydraulic engineering works. For European oak two Dutch standards were published in 1983 in the series Quality Requirements for Timber (KVH 1980), NEN 5476 Wood type European Oak. Unedged and NEN 5477 Wood type European Oak. Rectified. European oak complies with the requirements stated in Assessment Directive (BRL) 2908/01 Wooden dowels.
properties: :        

Durability of fungi:
- practical experience and field research i 2 
- field research i 2-3 
Sustainability of insects i Anobium G 
The sapwood is susceptible to attack by Lyctus 
Volumic mass (range) i 500-970 kg/m³
Shrinkage coefficient radial i 0.15
Coefficient of shrinkage tangentially i 0.26 %
Moisture content range 20-6 
Hardness (Janka) - face i N
Hardness (Janka) - longitudinal plane i N
Strength class i C20 C24 
Quality class A/B NEN 5477 European NPR 5493 

E_modulus (test) i 10000 10000 N/mm²
E-modulus parallel (rep) i 9500 11000 N/mm²
E-modulus perpendicular (rep) i 320 370 N/mm²

Bending strength (test) i 97 97 N/mm²
Bending strength (rep) i 20 24 N/mm²

Compressive strength parallel (test) i 50 50 N/mm²
Compressive strength parallel (rep) i 19 21 N/mm²
Compressive strength perpendicular (rep) i 2.3 2.5 N/mm²

Tensile strength parallel (rep) i 12 14 N/mm²
Tensile strength perpendicular (rep) i 0.5 0.5 N/mm²