Wood Drying - Types of Wood

Types of Wood

Wood is divided, according to its botanical origin, into two kinds: softwoods, from coniferous trees, and hardwoods, from broad-leaved trees. Softwoods are lighter and generally simple in structure, whereas hardwoods are harder and more complex. However, in Australia, softwood generally describes rainforest trees, and hardwood describes sclerophyllous species (Eucalyptus spp ).

Softwood, such as pine, is much lighter and easier to process than hardwood (such as fruit-tree wood, which is heavier. The density of softwoods ranges from 350 kg/m³ to 700 kg/m³, while hardwoods are 450 kg/m³ to 1250 kg/m³. Both consist of approximately 12% of moisture (Desch and Dinwoodie, 1996). Because of hardwood's denser and more complex structure, its permeability is much less than that of softwood, making it more difficult to dry. Although there are about a hundred times more species of hardwood trees than softwood trees, the ability to be dried and processed faster and more easily makes softwood the main supply of commercial wood today.