The terms ‘softwood’ and ‘hardwood’ do not indicate softness or hardness of particular timbers. In fact, some hardwoods are softer and lighter than softwoods. The main differences between hardwoods and softwoods are botanical, and relate to the way the tree grows and the timber is laid down.
| Leaves | Hardwoods have broad leaves, while softwoods are conifers and have more needle-like leaves. |
| Colour | Hardwoods often have darker coloured wood, while softwoods are invariably light in colour. (Note that there are a number of species of hardwoods with light coloured woods. |
| Density | Most hardwoods have thicker cell walls than softwoods. Hardwoods often have higher densities than softwoods. Again this is not a definitive test, but it does reflect most of the Australian species. |
| Microstructure | The essential difference between the wood from hardwoods and softwoods is the presence of vessels in hardwoods. These are continuous pipes running the length of the tree and serve as conduits for water and nutrients in the outer layers of wood in a growing tree. |
In hardwoods, the cells are closed and cannot function as conduits. In softwoods, the cells have openings to other cells. This means the cells are the nutrient conduits. The actual cells in the softwood species have the same function as the vessels in hardwoods. The open cell structure of softwoods makes them generally more receptive than hardwoods to preservative treatments to enhance durability.
Softwood species
In most parts of Australia, Australian grown pine will be readily available. Also some imported species such as spruce, imported pine, Douglas fir or the spruce pine fir (SPF) mix will seasoned and locally produced), Radiata, pinaster, slash, Caribbean pines.
| Species | Radiata Pine | Douglas Fir | Hoop Pine | Cypress |
| Appearance |  |
 |
 |
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| Seasoned or unseasoned and imported. (Most commonly used at Davids Timber) | Unseasoned and imported, SPF (an unseasoned imported spruce/pine/fir mix) | Queensland grown, mainly unseasoned | Mainly grown in Queensland or NSW |
Hardwood species
The species and sizes in which hardwoods are available has much more variation with location than the species and sizes of softwood available across the nation. The range carried in a given area will depend on what local mills are able to produce.
As hardwood forestry is quite dynamic, it is very likely that availability of structural hardwoods will continue to change over time. It is imperative to check on availability before specifying any structural hardwood.
| Species | Blackbutt | Spotted Gum | Iron Bark | Stringy Bark |
| Appearance |  |
 |
 |
 |
| Seasoned or unseasoned. Generally found in NSW, QLD and VIC. | Seasoned or unseasoned. Generally found in NSW, QLD and VIC. | Seasoned or unseasoned. Generally found in NSW and QLD. | Seasoned or unseasoned. Generally found in NSW, QLD and VIC. |
Larger cross-section hardwood members (bridge timber, poles and piles) can still be obtained in some parts of Australia, but availability of specific species probably also be available in a limited number of sizes.
