Modern garden decking can be made from a wide variety of tough and practical synthetic materials, but real, natural timber is still considered the most attractive and desirable decking material by many homeowners. When well-chosen and properly constructed, timber decks can provide just as much durability and longevity as plastic or metal alternatives—however, no two woods are ever quite the same, so choosing the right species of wood for your decking needs is key.
Fortunately for Australians, one of the very best decking timbers around grows right on our doorstep. Jarrah, a native eucalypt found across wide swathes of the country, has a number of remarkable properties that make it ideally suited to deck building, the most important of which are listed below:
Jarrah is an incredibly dense and durable wood, and a deck constructed partially or fully from jarrah wood will be able to stand the test of time better than most other timbers and decking materials. Its incredible density means it will not dent or crack easily under impacts, and the natural preservative oils contained within its pores give it an excellent resistance to damp, mould and fungal growth, even without the use of fungicidal wood treatments.
Jarrah is also highly resistant to the attentions of termites and most wood-boring insects, a rare quality amongst the hardwoods and softwoods commonly used to create decks. However, living jarrah does serve as food for the powderpost beetle, so insecticidal treatments are generally advised to prevent damage by these tenacious beetles.
Jarrah also possesses enormous load-bearing strength, and many older homes still contain structural timbers made from pieces of jarrah that are often decades old. As such, jarrah decks can support enormous weights without bowing or splintering, a particularly useful quality for large, heavily-furnished decks or raised decks by above-ground pools.
Just because jarrah was once considered a structural timber, you should not be fooled into thinking it looks as drab and ugly as your average structural wood. Jarrah has a distinctive and rich red-brown colour that can be enhanced easily with oils and stains and can compliment a wide variety of outdoor design choices. Jarrah is also less susceptible to fading caused by intense sunlight than some other woods (such as teak), so a jarrah deck can last for many years before it starts to grey and lose its vibrancy.
Because jarrah is a native Australian wood, the carbon cost of purchasing it is much lower than the cost of importing desirable hardwoods from elsewhere, particularly tropical woods taken from vulnerable rainforest habitats. You can further increase the environmental credentials of your new deck by choosing jarrah taken from plantation-grown trees—these jarrah varieties tend to be slightly lighter and softer than old-growth woods, but still perform as well as most other decking timbers.
However, to minimise the environmental impact of constructing a jarrah deck, there is a third option—using recycled jarrah reclaimed from demolished or renovated buildings. Jarrah taken from strcutural timbers, floorboards and other former uses can easily be re-purposed for use in decking and can often be picked up for much lower prices than unused jarrah.