The Essential Characteristics of Wood: What You Need to Know

We can do many things with wood, not only for your fireplace or as a source of heat. For example, it’s essential to know the basic characteristics of wood for insulation and structural purposes.

Wood is a natural plant product that the earliest Neanderthal could utilise for construction material. We can produce wood from various woody plants, including firs and deciduous trees. Many of the main physical properties of wood make it an essential material. It is robust and durable but lightweight enough for multiple applications.

Chemical composition

Hemicellulose, lignin, and cellulose with high water content are embedded in a matrix. These molecules are from the same chemistry family that makes the structure.

This structural tissue influences wood characteristics like heat and moisture resistance. Lignin gives wood fibers its adhesiveness.

Information about wood structure and formation

Trees are both live and dead tissue, with the dead heartwood in the centre still giving stability. Just below the bark sits the vascular cambium, which contains the secondary xylem vessels that transport water and nutrition up to the leaves. Individual trees grow outward by a little bit each year at their base. This is known as the root collar, and it aids in support of trees.

annual growth rings
Laburnum slice showing bark, sapwood, earlywood and summerwood.

A plant material that consists of wood fibre and cell cavities. The tree has an annual growth ring which you can see by slicing horizontally through the bark with a saw. Cut the trunk vertically in the radial direction to see parallel lines forming the grain or density pattern.

Wood growth rings have a pattern made of annual rings or seasonal patterns. Earlywood or springwood is usually lighter in colour than summerwood or latewood. Knots affect the structural aspects of wood. Though ornamental, this reduces local strength and increases splitting propensity.

Water and wood

Woods are a porous substance made of cells in long strands called fibres. It is very hygroscopic – absorbing moisture from the air and expanding to twice its size when wet.

It is made up of cellulose, hemicelluloses and lignin, which are compounds that make it rigid. Water causes the wood to swell in winter by providing more space for H2o molecules.

A tree has an internal highway, where there’s more than just liquids. It also contains an invisible amount of vaporised steam, known as humidity. They can also soak up other liquids and gasses inside them. Hidden moisture within freshly-cut pieces that may be between 40-200 per cent (fresh greenwood).

Drying wood reduces its water content, increasing its mechanical property and strength. This is because when the wood is wet, its fibres are soft and more susceptible to damage or deformation. Moisture removal stiffens fibres, improving the strength of wood.

Hardwoods and softwoods

They both come from vegetation, but the critical difference is the tree species and wood density.

Hardwoods are broad-leaved deciduous trees with seeds in fruits or pods. Softwoods are evergreen trees with needles and cones. Hard woods mature slower than their softer counterparts with loosely-packed wood cells. Though this is not a strict rule, some are soft (Balsa), and some softwoods are hard (English Yew).

Hardwood has a greater denseness than others affecting the strength and hardness of wood. Often used in decorative woodwork because of their colours and long-term durability. Because of their workability and cost, soft woods are cheaper and better for household joinery.

How many sorts of wood are there?

There are three main types of wood: engineered wood, hardwood and softwood.

What you choose will depend on what you want to use it for and how much money you have handy. Solid wood is an organic material with many applications. There are hundreds of varieties of commercial wood, some more widespread than others.

Milled from coniferous trees, some commonplace softwoods are:

  • European spruce.
  • Eastern white pine.
  • Hemlock.
  • Cedar.
  • Redwood.
  • Douglas-fir.
  • Larch.

There are many hardwoods which include:

  • Birch.
  • Boxwood.
  • Beech.
  • Cherry.
  • Hickory.
  • Sycamore.

Manufactured products

Engineered wood is manufactured with manipulated wood. Dimensional stability and a flat surface finish are two features of these wood composites. Today’s market has many engineered products, including particle board and plywoods.

Engineered wooden boards

OSB

Orientated strand board: is an engineered wood product often an alternative to plyboard. It has a distinct texture and, as a result, does not have the same level of smoothness or finish as other sheet goods. OSB costs considerably less due to its base composition.

Commonly found as construction wood for 1st fix. It can be sheathed on floors, walls, and roofs to help as an insulator. Also, perfect for utility tasks like boxing in piping or electrical wiring. Yet, it’s not utilised by fine woodworking companies because it doesn’t have the quality of other composite materials.

MDF

MDF is engineered from compressed sawdust then formed into blocks or sheets. Often used for kitchen cabinets and floorboards because it can be moulded into any shape. It doesn’t crack or split like other types of wood. Though not suitable for moist conditions, it will blow up in thickness.

According to some people, the chemicals that MDF emits into the environment may harm human and animal health.

Plywood

Plywood is a strong wood that has an odd number of thin sheets. This form is stronger than its naturally occurring counterparts and allows for composite panels.

Composed of multi-layers of veneer, glued together at opposing angles with adhesive. It comes in various thicknesses for making cabinets, shelves and flooring paneling. There are four plywood grades with a good side and a rough side. A through D, with each grade representing differing qualities within the board. The letter (A-D) means better face quality and fewer defects present on any piece. In contrast, the lower letter indicates a lower quality on the back and more flaws.

It is created from thin laminated veneer lumber. Useful not only as a building’s structural panels but also in cabinet furniture.

What is pressure treated lumber?

Pressure-treated lumber is suitable for building materials due to its durability and resistance to rot, pests, and bugs. Pressure-treated with chromated copper arsenate to resist bacteria, moisture or fungal decay damage.

Safe to use while wearing a mask, but not safe for food contact. Ideal for woodworking projects, like decking or outdoor furniture. Typically guaranteed for ten years in the UK, it can be re-treated with preservatives.

What is the difference between lumber, timber and wood?

There is often confusion about the interchangeability of words around these natural resources. The term ‘wood’ refers to the fibrous tissue found in stems and roots of trees that supports and enables it to absorb sunlight for photosynthesis. Wood also allows the transfer of nutrients to growing tissues and foliage.

Timber can be applied at any stage after felling – raw materials or finished goods. In some countries, it refers to sawn logs for building. In the United States and Canada, it often refers to felled trees.

They are all terminologies to describe what people do with it once felled.

Why are forests so important?

Forests are vital to the ecosystem. They give environmental benefits and a habitat for wildlife and plants. Forestry creates new woodlands that future generations can enjoy. They are a sustainable asset, meaning that woodland can regrow once chopped down.

People also use wood products to improve the environment by replacing non-renewable plastics.

Playing a vital role in regulating climate and rainfall patterns by releasing oxygen back into the atmosphere. They are also responsible for storing carbon dioxide, which affects greenhouse gas. Extra greenhouse gases may cause global warming and climatic change, which is of utmost importance. Earth’s natural forces are tied to our survival, so rainforests must provide these services.

In 2018, North America harvested approximately 439 million cubic meters of wood, with 67% of it used for construction materials.

What is wood used for?

Each piece of wood has many uses and is an affordable and renewable energy resource. It also comes in many colours and varieties.

A versatile resource that has been in use since the beginning of time, here are the most common ten uses of wood:

1. HomebuildingDry wood is inexpensive and easy to use. It’s excellent for making homes, frames for doors and windows.
2. Quality FurnitureIt can be shaped into furnishings that remain appealing after centuries.
3. PaperPaper has been made from wood for centuries. In recent years recycled paper of high quality with low environmental impact.
4. FlooringEngineered floors are often beech or walnut with the ability to resist decay and mildew.
5. Planks/SawdustSawdust is a kind of wood waste that may turn into a variety of goods such as wood chips, fuel pellets, and shavings.
6. WoodworkingSome individuals use mahogany or Koa to create long-lasting hobbies and crafts things.
7. Musical InstrumentsThe violin family, guitars and harpsichords all use wood for their soundboard or body.
8. Household UtensilsWooden spoons have been stirring food in pots since Medieval times! In addition, wooden spatulas are excellent for cooking everything from pancakes to omelettes.
9. Sporting equipmentWillow and bamboo are often employed in making cricket bats and other sports equipment.
10. Ship BuildingDifferent wood classifications were chosen for their characteristics and purpose. For sturdiness and lightness, fir is often used for ship masts and teak for decks.

Individual wood descriptions

The common characteristics of wood help determine which is appropriate for a project. The physical qualities may vary, with some being heavier or softer than others.

This section will give you an overview of each wood’s properties. My opinion on using them and things learned over twenty years.

Wood species chart

Ash wood

Suitable for a wide range of applications. Now becoming difficult to find because it’s highly susceptible to Emerald Ash Borer. If you are in an area where they grow naturally, this might be more environmentally friendly. Similar attributes to white oaks but at a lower price point.

The term “olive ash” is a colourful description of some that resemble olivewood. Its lovely yellow hues and brown streaks set it apart from regular Fraxinus anomala.

Beech wood

Beechwood has a straight and tight pattern, perfect for interior cabinet making. It can suffer from shrinkage and swelling when exposed to high humidity.

Spalted beech is sought after by woodworkers for the figured dark lines. Sometimes blackened lines are present; the more lines, the more desirable. The fungus can cause problems if not caught at the right time as the fungi eat the wood making it weak and punky.

Unique spalted beech

Cherry

Cherry is a dense wood reddish-brown in colour with moderate tensile strength. Easy to work with and turns a golden colour as it ages. Beautiful colours but can be difficult to finish. It will darken, and blotchy flaws are unavoidable as the colour varies and bleeds through.

Buckeye burl

The Buckeye tree comes from the Eastern United States and California. Burls can weigh in at up to three thousand pounds and rest under the earth in the root wad its base. I have not linked to a technical description as the existing wood info does not do it justice. To be usable, this needs impregnating with resin in a vacuum chamber and has dyes added for effect.

Swirls of yellow, brown, blue and red now and then. Buckeye Burl dries fast, which can be good in many different projects. About 60% to 75% of the burl gets cut away before starting.

Coolabah Ballpoint Pen

Coolabah

Australian woods are tough, and this is no exception. However, this is not as dusty as some. Beautiful figure and colours, also costly and not available in large quantities.

Cocobolo

From the Dalbergia family, Cocobolo is a heavy, oily wood. Sharp tools are a must, then no problem working with it. Many woodworkers love it for the gorgeous colours it produces while woodturning.

Curly Maple Pen Pencil

Curly Maple

Curly maple is not a species but a description of the attractive wood. The pattern can be found in nearly all Acer’s, most pronounced with a quartersawn board. It has many different grades, which significantly impacts pricing. Tends to be economical when compared to other figured woods.

Douglas Fir

Douglas fir is a softwood from the Pacific Northwest and the Eastern coast of North America. It is a durable wood that has rot resistance and low shrinkage. It is also straight-grained and easy to plane.

Fir is economical and robust to use for applications. In addition, it can be difficult to stain because it has a tight texture. It is often used for utility and frame constructions when finishing is not crucial.

Elm

Known as the “English Elm,” native to Western Europe. The English Elm varies from light or medium reddish-brown in colour. The bark is typically grey-brown and smooth, with a thin peeling layer on top.

Fairly common throughout the USA for residential use due to its ease of growth and beauty. Open-pored that is darker than oakwood. The pores will need filling on a fine tabletop.

Before modern plumbing, it was employed as a water pipe with excellent rot and decay resistance.

Holly

The Holly can seem either upright and graceful to drooping and often weeping. Found mainly in Europe, northwest Africa, southeast Asia, and North America. The Holly usually grows 50-65 ft tall and has a trunk diameter of 1-2 ft.

Holly scarce to find that’s well-conditioned. If not conditioned properly, it will appear a dirty grey colour. Difficult to get in any quantity because of slower growth. Heavy and pale, popular for turning or inlay banding, as seen in the American federal period.

Kingwood

Kingwood is a dark-coloured wood that turns very well and takes a high polish. It has a distinct odour when being worked. Kingwood is frequently seen as small turned objects. Cost is on par with other exotics in the Dalbergia genus, like African Blackwood and Cocobolo.

A kind of rosewood that was initially called Princes Wood. It was adopted in the 17th century on cabinets and tables for ruling French Kings Louis XIV and Louis XV.

Ideal for inlays, decorative veneer and speciality items with an extremely high density.

African Mahogany

African Mahogany is closely related to Cuban mahogany and one of the three true mahoganies. It comes from the Khaya genus and grows to be about 130 feet tall with a diameter of 3-5 feet. The specific Janka hardness is 1,070 lbf (4,760 N). It has a crushing strength of 7,100 lbf per inch and is usable for boat building and interior trim.

Oak

Oak expands and shrinks based on temperature and moisture conditions. It has a beautiful pattern, with the European white oak sturdy and rot-resistant. In use throughout England for hundreds of years on both land and the sea. Many of the grand old English houses have quartersawn wood walls of Oakwood. It was favoured by the old craftsmen, undemanding and easy to work with.

Pau Rosa

Pau Rosa, also known as the Pink Rosewood, has become increasingly rare. It can reach between 70-90 ft with a 2-3 ft circumference. The heartwood can vary from pink or yellow to dark reddish-brown. This is common in Brazil but becoming less commonly seen in the wild due to habitat destruction.

It has a high cutting resistance but is also excellent for turning and finishing. The process is more rewarding when the outcome is successful because of the challenge involved.

Pine

Pine trees are widespread and can be utilized for many different projects. Commonly employed for carpentry, cheap furnishings, and other purposes. It can be stained to give it an appealing look or painted. The SPF wood (Spruce, Pine and Fir) offers planks sold under generic terms like Whitewood.

Pinewood is known for rapid growth in sustainable forestry conditions. They are a non-toxic living source that can be recycled into new functional wares.

Walnut

A walnut tree can live for centuries, but it is also one of the more expensive hardwoods. Because it is a very dense wood with even colour, it is often used in high-end luxury cars and gun production. Much more affordable than exotics that are rarer or harder to work with, like mahogany or rosewoods.

In addition, you can also use it for musical instruments such as guitars and violins. A popular choice because of its durability and tone quality.

Wenge

Wenge is a tropical tree that belongs to the Meliaceae family and growing up to 90 feet tall with a diameter of 3-4 ft.

Deep chocolate and dark brown can be used in veneer paneling and for it’s acoustic property. It is challenging to work with using hand or machine tools. Care must be taken when handling because It’s very splintery and septic-prone.

Care and thought are needed for pens depending on the orientation and the finish. Depending on the finish, the pen can end up jet black. If the grain is running in the wrong direction, there is a solution in this article-treating the wood.

Zebrano

Zebrano has stripes that look like zebra-like patterns. It has an unpleasant smell and coarse texture, which gives it unique qualities. Zebrawood can make tool handles, cabinetry and skis due to its strength for weight.

The price tag varies from pricey to very expensive depending on the variety, and difficult to come by. Attention is needed when figuring wood grain direction for pens getting the best effect.