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Definotion, History, Types and Deffects of Wood



What is wood?

Wood is a tough, fibrous cellular substance that makes up most of the item and brances of
trees beneath the bark.

What is the origin of wood?

A 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known
plants to have grown wood, approximately 395 to 400 million years ago.[4] Wood can be dated
by carbon dating and in some species by dendrochronology to make inferences about when a
wooden object was created.

People have used wood for millennia for many purposes, primarily as a fuel or as a
construction material for making houses, tools, weapons, furniture, packaging, artworks, and
paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to
the prevailing climate at that time.

Types of Woods

Hardwoods are deciduous trees that have broad leaves, produce a fruit or nut and generally go
dormant in the winter. North America’s forests grow hundreds of varieties that thrive in
temperate climates, including oak, ash, cherry, maple and poplar species. Each species can
be crafted into durable, long-lasting furniture, cabinetry, flooring and millwork, and each offers
unique markings with variation in grain pattern, texture and color.

Softwoods or conifers, from the Latin word meaning “cone-bearing,” have needles rather than
leaves. Widely available U.S. softwood trees include cedar, fir, hemlock, pine, redwood and
spruce. In a home, softwoods primarily are used as structural lumber such as 2x4s and 2x6s,
with limited decorative applications.

Softwood Lumber Classification

Yard lumber - Lumber of those grades sizes and patterns which are generally intended for use
in an ordinary construction or general building purposes.

Structural lumber - Lumber which is 2in (50 mm)in normal width and thickness to be used
where working stresses are required.

Factory and shop lumber – lumber that is produces or selected primarily for remanufacturing
Tropical Hardwoods

Tropical Hardwoods, including mahogany, rosewood, teak and wenge - are not native to North
America. They grow in the tropical forests of the world and must be imported for domestic use.
While some tropical hardwoods can be used for interior applications, including flooring, the
color, grain pattern, hardness and luster of many imported woods differ from those of American
hardwoods. For more information on non-native species, refer to the “Don’t be fooled” article.

Wood Defects

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