Continuing from Back to Basics – Types of Hardwood, this week we will look at softwoods. As many woodworkers know, one of the primary considerations when embarking on a woodworking project is choosing the right wood. Every type has a unique set of properties, and either by accident or design, time has taught us which woods are ideal for what purpose. Examples can be found all around us, and they not only inform our choice of wood, but also demonstrate the effects of time and place on a material. For example, the characteristic concave floorings of old oak-framed buildings.
So, conversely, onto softwoods! Perhaps due to the somewhat misleading name, the definition and characteristics of these woods may throw up a few surprises.
What are softwoods?
Softwood is wood from gymnosperm trees. This definition relates to a particular characteristic, which includes the recognisable conifers. They are seed-producing plants that tend to lack an outer layer that protects the seeds. For example, seeds exposed on cones are a typical feature of softwood trees. Perhaps surprisingly, softwoods are not necessarily soft. Indeed, some softwoods are harder than hardwoods. For example, Southern Yellow Pine (a softwood) is harder than black walnut or black cherry (both hardwoods).
Characteristics of softwoods
Weight. Softwoods are typically less dense and therefore lighter than hardwoods. They tend to be chosen for applications where weight is a primary consideration, such as boat superstructures.
Flexibility. Softwoods have less dense wood fibres. As such, they are more flexible and therefore easier to work with when bending is required.
Growth time. Softwoods can reach maturation in 20–40 years, making them an ideal choice for plantations used in industry.
Grain colour. They tend to have a lighter grain. This makes them particularly favourable for furnishing softly lit indoor spaces.
Cost. As they take less time to grow, they are cheaper to produce.
Did you know?
The global use of wood comprises about 80% softwood.
Five lightest woods
- Balsa (Ochroma pyramidale)
160–200 kg/m³ / Extremely light, used in models and aerospace.
- Cedar (Cedrus spp.)
350–450 kg/m³ / Light, durable, and aromatic, used in furniture and outdoor applications.
- Pine (Pinus spp.)
400–600 kg/m³ / Common softwood, light and inexpensive, used in furniture and construction.
- Spruce (Picea spp.)
400–550 kg/m³ / Light, strong, and used in construction and musical instruments.
- Poplar (Populus spp.)
400–500 kg/m³ / Light hardwood, easy to work with, used in furniture and cabinetry.
Softwood examples
Cedar (Cedrus)
These are giants. They can grow to over 40 metres, sometimes reaching heights of 60 metres. They are commonly found in Mediterranean and Himalayan regions, typically growing above 1,000 metres altitude. They are grown and harvested in plantations in temperate regions where their relatively quick maturation makes them a choice material for paper production. The scented wood and high resin content are known to repel moths – a quality that has made it a choice material for cabinets, drawers and wardrobes.
Redwood (Sequoia)
Even bigger than cedars, redwoods are a type of coniferous tree found in the Northern Hemisphere. The largest and tallest tree in the world is a redwood, and is found in the state of California in the US. It measures an amazing 83.8 metres tall. Despite this seemingly immortal status, redwoods are increasingly being lost to wildfires, and the species is listed on the IUCN Red List as endangered. The wood is straight grained with a reddish-brown colour, and is resistant to decay and insects.
Douglas Fir (Pseudotsuga menziesii)
Another type of conifer, Douglas firs can also grow to impressive sizes, while some are believed to have lived for over a thousand years. They have thick barks, especially on mature trees, and this makes them especially resistant to fires. Historically their uses have ranged from medicines to canoes. They have since been used as plantation trees as they grow quickly. Perhaps their best-known use is as the common Christmas tree. The timber is popular in timber frame construction, as well as flooring, veneer manufacturing and ship manufacturing.
Larch (Larix)
They are found in the arboreal forests of the Northern Hemisphere, such as those found in Canada and Siberia. Although a form of conifer, larch lose their leaves in autumn. The timber from larch is durable and resinous with a distinctive grain, and is used in furniture making, shipbuilding and exterior cladding. European larch was introduced to the UK in the 17th century for timber plantations.
Pine (Pinus)
There are well over a hundred known species of pine, making it the largest genus among the conifers. They are accustomed to drier conditions, and can be found in the Mediterranean basin and the dry tropical forests of South-East Asia. Pine is used extensively around the world for a broad range of uses, including construction, furniture making and window frames. Once harvested it is prone to rot, so pine is treated if intended for outdoor use. Methuselah is a pine that is nearly five thousand years old, and is considered to be the oldest living organism on earth.
Uses for woodwork
Cedar of Lebanon
Joinery, outdoor furniture, building construction, gates and fences. Interesting logs are sliced into veneers for decorative panelling and plywood facing.
Redwood
Rustic furniture and flooring, exterior joinery, cladding (siding), shingles, vats, coffins, posts, wine casks, fencing and decking. The bark is used for particleboard. The wood is rotary cut for plywood, and cut for veneers. Vavona burr (burl) is prized for its decorative qualities.
Douglas Fir
Veneer, structural beams, building, domestic and factory flooring, formwork, packing cases, marine piling, interior and exterior joinery, cabins, vats and railway sleepers.
European Larch
Door and window frames, flooring including parquet, staircases, boats and ship building, poles, piling, posts, fencing and shingles. It is also sliced to make decorative veneers.
Western White Pine
Furniture, interior joinery, windows, doors, shelving, trim, drawing boards, boat and shipbuilding, flooring, woodware, matches, packing cases, roofing, pulp, particleboard and plywood. Interesting pieces are sliced into veneers for panelling.
How softwood is treated for durability
Softwoods are treated to make them stronger, longer lasting, and resistant to pests and weather damage. Here are some common methods used:
- Pressure treatment: This process forces chemicals deep into the wood to protect it from rot, insects and fungi. The chemicals used are usually copper based, making the wood more durable for outdoor use.
- Heat treatment: Wood is heated to high temperatures in a controlled environment. This reduces moisture and makes the wood more resistant to decay. It also changes the wood’s colour, often darkening it.
- Oil treatment: Applying oils like linseed or tung oil helps the wood stay dry, reducing the chances of cracking and splitting. It’s often used for garden furniture or decking.
- Surface coatings: Coating the wood with varnishes, paints or stains helps protect it from the sun, rain, and wear and tear. These coatings also improve the wood’s appearance.
- Borate Treatment: A safe, non-toxic solution that protects wood from insects like termites and fungi. It’s usually used indoors or for dry areas, as it can wash away in wet conditions.