Wood is the main substance in trees. It is mainly formed by the xylem vessels which carry water up the plant. Wood is used to make buildings and furniture, and also for art. Firewood is a fuel. Paper is made from wood fibres. Wood is a renewable resource although it has become scarcer in recent centuries.
Wood is very hard to cut, but it is also very strong. A lumberjack is a person who cuts down trees. After a tree falls, the wood in it can be cut into long, straight pieces called lumber. Lumber can then be used to make posts, or put together with nails, screws, or even glue to make wooden frames for other shapes.
Wood comes in many different kinds. Oak, maple (hardwood) and pine and redwood (softwood) are widely used types of wood. Woods are usually divided into softwood (from conifers) and hardwood from flowering plants.
For a long time and even today, many buildings, mostly houses, have been made of wood. To build a house with wood, lumber is put together into frames that are the shape of each wall, floor, and roof of the house. Then the frames are placed into the shape of a house. Then the frames can be covered to make solid walls. Sometimes the walls are made of more wood.
When the outside of a house or building is covered in wood, the wooden pieces are usually flat and stacked. These pieces are called shingles. Wood is also sometimes used in other parts of the house, like doors and staircases. Wood is also used to make fences.
Carpenters make houses of mostly soft wood such as pine. For many kinds of furniture they use harder wood such as maple or oak. When someone builds something with wood, they usually paint it. Paint protects and beautifies the wood. Some people like the look of wood, so they put clear paint called varnish on it. This helps to protect the wood and gives it a shiny finish.
Wood is turned into paper in large factories called paper mills. The wood is first chopped into small chips and cooked with chemicals in large vessels. The chemicals separate a substance called cellulose off the wood fibres. The cellulose is then added with other chemicals and additives, and pressed into paper in large machines called paper machines. Most paper is made from pine, spruce and eucalyptus.
- Wood -Citizendium