Sometimes it’s good to take it back to basics. As with many interests, there are lots of woodworking specialities, approaches, products and processes. As such, it can be easy to lose sight of the fundamentals – in this case, the types of wood available. One of the joys of working with wood is the wide variety of types to choose from, each with a unique set of properties. Wood can be light, strong, pliant, heavy, aesthetic, smooth, rough, rot resistant, fire resistant – in short, a whole manner of properties that not only make different woods appropriate for certain uses, but also provide an aesthetic beyond their functional application. Think, for example, of the swirly grain patterns of a simple pine table top. This is a great choice of wood for furniture that’s cheap, functional and hard-wearing. But would pine make a suitable choice for planking a rowing boat?
In this article I’m going to take a closer look at hardwoods, and draw on some common examples to explore their properties and how they can be used appropriately in woodworking.
What is a hardwood?
Hardwoods come from angiosperm trees – typically deciduous trees that shed their leaves during winter. These species specialise in maximising growth during the summer months when there is an abundance of light, and minimising the loss of energy and moisture during the cold winter months, when solar energy is in short supply. This variation is what creates growth rings. The wider, lighter circle is the wood grown during summer, and the darker rings are the winter growth. This adaptation has enabled hardwood species to thrive within the temperate climates of North America, Europe and Eastern Asia, where there is regular rainfall. Deciduous trees are also found in tropical rainforests.
Characteristics of hardwood
Density. Hardwoods are dense and heavy. The alternation of the summer and winter seasons causes them to grow more slowly, creating a dense and strong wood.
Decay resistant. Hardwoods are highly resistant to decay. Their compact structure of tightly packed cells is an effective barrier against bacteria and fungi. They also contain a high amount of lignin, a chemical compound that helps prevent pathogens from establishing within the wood.
Fire resistance. Because of their high density, hardwoods burn more slowly, and so are more fire resistant than softwoods. Softwoods also contain more air pockets, causing them to burn more easily.
Grain. Hardwoods have a close grain as a result of their slower growth within temperate regions.
Colour. Hardwoods are typically darker woods.
N.B. Not all hardwoods have these characteristics. For example, balsawood is a hardwood that is lightweight and very soft.
Top 5 heaviest woods
Quebracho (Schinopsis spp.)
77.1 lbs/ft³ (1,235 kg/m³)
Known as “axe breaker”, this wood is among the hardest and heaviest globally.
Lignum Vitae (Guaiacum officinale)
78.5 lbs/ft³ (1,257 kg/m³)
The heaviest wood in the world, it’s endangered and listed under CITES. Verawood is a suitable alternative.
African Blackwood (Dalbergia melanoxylon)
79.3 lbs/ft³ (1,270 kg/m³)
Highly prized and historically considered the original “ebony”.
Itin (Prosopis kuntzei)
79.6 lbs/ft³ (1,275 kg/m³)
A dense, dark South American wood, often used as an ebony substitute.
Black Ironwood (Krugiodendron ferreum)
84.5 lbs/ft³ (1,355 kg/m³)
Exceptionally dense, rare and ideal for small turning projects.
Examples of their use
Oak (Quercus)
Perhaps the most well-known of hardwoods, oak is incredibly strong, heavy and resistant to rot. It has been used extensively in construction through the centuries, and examples of its durability and impressive grain can be seen in many forms of historical architecture. It was also a favoured choice for boat building prior to iron and steel. It is said that over 2,000 oak trees were used in the construction of HMS Victory, the flagship of the British navy in the late 1700s.
Maple (Acer)
A common tree among the temperate forests of the northern hemisphere, and synonymous with Canada, maple is a hard and durable wood known for its abrasion resistance. The sap is well-known for being sweet, and was first discovered by indigenous people of North America. Maple is also used for furniture and cabinet making, prized for its light colour and interesting grain texture. The smoky flavour of Tennessee whiskey comes from filtering it through charcoal made from maple trees.
Ash (Fraxinus excelsior)
Widely seen across Europe and America, its practical use is limited by its tendency to rot. As such, it is typically used for indoor spaces, such as floor fitting, furniture and cabinetmaking and veneer. Ash has undergone a dramatic decline across Europe due to Ash dieback disease, which is a fungus that defoliates the infected tree. Ash trees provide a habitat for many types of wildlife, including nuthatches, woodpeckers, bullfinches, insects and bats.
Beech (Fagus)
Beech trees can grow to impressive sizes. They are known for dropping healthy-looking branches following high rainfall, earning them the moniker “the widow maker”. The wood has a light appearance with a predictable grain. It is resilient, and is commonly used for making cooking utensils, tool handles, sports equipment and musical instruments. Beech trees are associated with femininity in Celtic mythology. Fagus was the god of beech trees.
Mahogany (Swietenia macrophylla)
Highly valued for its dark red appearance and durability, the wood was revered as a status symbol and sign of wealth. As such, the mahogany tree has been unscrupulously harvested for centuries, and is now on the CITES (Convention on International Trade in Endangered Species) endangered species list. Historically mahogany has been used for canoe building, furniture and musical instruments, as well as construction and carvings. Mahogany trees can live for over 350 years.
Uses for woodwork
European Oak (Quercus robur) – Furniture and cabinetmaking, restorative joinery for historical buildings. Pews, pulpits for churches, kitchen cabinets, coffins, boats. Cooperage for wines, cognac and beer. Oak is sliced for decorative veneers, and rotary-cut for plywood.
Soft Maple (Acer rubrum) – Furniture, including kitchen cabinets and office furniture; musical instruments, domestic flooring, interior joinery, core stock and truck bodies. It is also rotary cut for plywood and sliced for figured decorative veneers.
American Ash (Fraxinus americana) – Quality furniture, interior joinery, boatbuilding and built-in kitchens, Other uses include sports equipment, such as oars, paddles, bats and cues, and handles for workshop and garden tools. It is also a good source for decorative veneers.
European Beech (Fagus sylvatica) – Solid and laminated furniture such as desks, benches and chairs (including bentwood furniture), quality joinery, kitchenware, tools, tool handles and workbenches, turnery, musical instruments, toys, bobbins, domestic flooring, decorative veneers and plywood.
African Mahogany (Khaya ivorensis) – Furniture and cabinetmaking, interior joinery, bank, office and shop fittings, and boatbuilding. It is also sliced for veneers and rotary-cut for plywood.
Environmental considerations
The responsibility to protect the environment falls on all of us. Woodlands and forests are home to many animals and fragile ecosystems. As such, when choosing wood, it’s important to make informed choices. Here are a few things to look out for when choosing your timber.
- Source: Ensure your timber comes from a legal, sustainable source.
- Species: Carry out research to ensure the timber type is not endangered.
- Certification: Whether the timber is certified by a third party. For example, FSC (UK and US).
- Local sourcing: Whether the timber is sourced locally to minimise CO2 footprint.
For more information on endangered tree species check the CITES Species Checklist