Birch lumber is a common lumber that comes from a number of tree species native to North America. The wood of these trees is dense, and the texture is uniform. Lumber is taken from both the sap wood, which is the outer section of the trunk just below the bark, and the inner section, known as the heart stock. In some birch lumber, the sap wood contains small knots.
Birch lumber comes in a number of colors. White birch, which appears as a light creamy wood, comes from the paper or gray birch tree. Yellow birch is one of the most common types of birch wood, and comes, as its name suggests, from the yellow birch tree. Red birch lumber is the heart stalk of the yellow birch tree.
Lumber from birch trees is easy to treat and remains stable once treated. The green, or untreated lumber from the birch tree holds a lot of water and can lose nearly 16% of its total volume as it dries out. The lumber is prone to bending and twisting if it is not weighed down while drying out. After it is dry, the wood is susceptible to decay and infestation from insects and fungus and needs to be treated to prevent damage. It holds up well when kept indoors, though it deteriorates rapidly outside and is not generally suitable for outdoor projects.
Reasonably inexpensive, birch is used for a variety of projects as well as for firewood. It is one of the most commonly used hardwoods, largely due to its low price. In addition to its usefulness as a lumber wood, birch can be used to build furniture, toys, paper and tooth picks.
Birch lumber comes from a number of different species of birch trees. These trees are in the Betula genus and are related to oak and beech trees. Most birch trees grow to heights of 40 to 50 feet (about 12 to 15 m). On many species of birch, the bark peels easily, giving it a papery quality. The bark, especially from the white birch tree, also is sturdy and flexible enough to be used in craft projects.
Birch is a hardy tree with a high germination rate. It readily moves into new areas and grows rapidly to maturity. The leaves of all trees in the birch family change color and drop off the trees in autumn and winter.