Birch is a broadleaved deciduous hardwood tree of the genus Betula in the family Betulaceae, which also includes alders, hazels, and hornbeams, and is closely related to the beech/oak family. Birch species are generally small to medium-sized trees or shrubs, mostly of temperate climates. The bark of all birches is characteristically marked with long, horizontal lenticels, and often separates into thin, papery plates, especially upon the paper birch. It is resistant to decay, due to the resinous oil it contains. Its decided color gives the common names gray, white, black, silver and yellow birch to different species.
The wood of all the species is close-grained with satiny texture, and capable of taking a fine polish; its fuel value is fair.
Birch wood is fine-grained and pale in colour, often with an attractive satin-like sheen. Ripple figuring may occur, increasing the value of the timber for veneer and furniture-making. Birch wood is suitable for veneer, and birch plywood is among the strongest and most dimensionally stable plywoods, although it is unsuitable for exterior use.
Birch plywood is made from laminations of birch veneer. It is light but strong, and has many other good properties. Birch plywood is used to make longboards (skateboard), giving it a strong yet flexible ride. It is also used (often in very thin grades with many laminations) for making model aircraft.
Wood pulp made from birch gives relatively long and slender fibres for a hardwood. The thin walls cause the fibre to collapse upon drying, giving a paper with low bulk and low opacity. The birch fibres are, however, easily fibrillated and give about 75% of the tensile strength of softwood. The low opacity makes it suitable for making glassine.
Country of origin | Latvia, Estonia, Lithuania |
Diameters | 12+ cm; 18+ cm |
Lengths | 2,7m (+ 10 cm); 3,0m (+ 10 cm) |
Grades | A, B, C (C 10% - max) |