Understanding Basic Information about Timber and Wood for Interior Design and Decorating

Trees

Timber comes from trees.

There are three main parts to a tree:

The Crown - which holds the leaves.

The Trunk - which supports the crown and the roots, which support the trunk and the crown. Carbon dioxide passes from the air into the leaves and with the aid of sunlight and chlorophyll in the leaves combines with compounds in the leaf cells to build up food substances. These are sugar and starch.

The Roots - absorb water and mineral salts from the soil.

The Characteristics of Softwoods and Hardwoods

Softwoods

These trees are non-porous; they are usually evergreen conifers. They have needle like leaves and uncovered seeds.

Hardwoods

These trees are porous, and usually deciduous. They have broad leaves and covered seeds.

Parts of a Tree

Pith

The centre of tree growth. The pith is prominent in Pines but hardly visible in other varieties.

Heartwood

This is the fully developed mature section in the centre of the tree. Due to the gum or resin contained in the wood cells it is usually darker in colour than sapwood. Its main function is to support the tree as it is inactive (ceased growing).

Sapwood

This is newly formed wood that surrounds the heartwood. It is lighter in colour and softer than the heartwood. Water and dissolved minerals are conducted to the leaves through the cells of the sapwood. The sapwood gradually matures and hardens into heartwood as the tree grows. Sapwood is less resilient to decay and insect attack.

Cambium Layer

Surrounding the sapwood is a layer of cells, just under the inner bark. This is where the growth of the tree takes place through the division of cells. The cambium layer creates new sapwood on the inside of the previous years growth and new inner bark on the outside.

Bark (or Cortex) - Outer Bark

This is the rough corky layer on the outside of the tree. It acts as a layer of protection against the cold, extreme heat or insect attack.

Inner Bark (Phloem or Bast)

On the inside of the outer bark is a thin green layer that carries the plant food or sap from the leaves to the cambrian layer throughout the tree. This is the inner bark.