There are two main types of lumber. It 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. It is classified more commonly made from softwood than hardwoods, and 80% of lumber comes from softwood.
In the United States milled boards of wood are referred to as lumber. However, in Britain and other Commonwealth nations, the term timber is instead used to describe sawn wood products, like floor boards.
In the United Kingdom, the word lumber is rarely used in relation to wood and has several other meanings, including unused or unwanted items. Referring to wood, Timber is almost universally used instead.