Dimensional lumber

Lumber (American English; used only in North America), or timber (used in the rest of the English speaking world) is wood that has been processed into beams and planks, a stage in the process of wood production. Lumber may also refer to currently un-needed furniture, as in Lumber room, or an awkward gait, ultimately derived from the look of unfashionable and unwanted furniture.

Lumber may be supplied either rough-sawn, or surfaced on one or more of its faces. Besides pulpwood, rough lumber is the raw material for furniture-making and other items requiring additional cutting and shaping. It is available in many species, usually hardwoods; but it is also readily available in softwoods, such as white pine and red pine, because of their low cost.Finished lumber is supplied in standard sizes, mostly for the construction industry—primarily softwood, from coniferous species, including pine, fir and spruce (collectively spruce-pine-fir), cedar, and hemlock, but also some hardwood, for high-grade flooring.

Lumber is mainly used for structural purposes but has many other uses as well. It is classified more commonly as a softwood than as a hardwood, because 80% of lumber comes from softwood.

In Australia, Ireland, New Zealand and Britain, the term describes sawn wood products, such as floor boards. In the United States and Canada, generally timber describes standing or felled trees, before they are milled into boards, which are called lumber.

Timber there also describes sawn lumber not less than 5 inches (127 mm) in its smallest dimension. The latter includes the often partly finished lumber used in timber-frame construction.

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