The Timber Decks Guide

Learn about Timber, Composite and Modular Decking Options

Timber Decks Guide

Timber decks are perfect solutions for those who want some extra outdoor space. As outdoor living spaces, decks are a beautiful, functional addition to your home. A great area to entertain, a smart investment, and provide a way to reconnect with nature. In addition to enhancing your outdoor lifestyle, decks offer a cost-effective way of adding value to your property. However, since they come in softwood, hardwood, composite materials, aluminum, and modular constructions, making the right choice might not be as easy. You need to take several different factors into account including your budget, location, and prevailing weather conditions among others.

Advantages of timber and why it is a popular choice

Timber decks are the most popular choice, mainly because timber offers more benefits than all the other decking materials. Here is a deeper look at the benefits provided by timber decking.

Stunning visual appeal

While different types of timber are used for decking, their naturally stylish and warm visual appeal can transform your backyard into an elegant entertaining area. Apart from offering timeless beauty, timber decks can greatly aggrandize the appearance of your entire property.

Increases property value

With outdoor activities playing a huge part in modern lifestyles, designs for exterior spaces must be of the same quality and detail as interior designs. Installing a high-performance deck will potentially increase the value of your property and improve your return on investment.

Incredibly practical

By providing additional space for growing families and a comfortable environment for parents who want to stay connected to the children playing outdoors, timber decks offer a viable solution to the needs of indoor-outdoor families.

Strong and durable

Aside from the fact that strength and durability are important for functionality, most of the wood species used for decks are long-wearing and therefore perfect for high traffic areas.

Easy and quick construction

As a decking material, timber construction is fast and efficient. You can design and build a wooden deck any time of the year. They can be easily installed as a DIY project or you can have a professional deck builders design and construct it for you.


Timber serves as a natural insulator because of the air pockets within its cellular structure. Additionally, timber is 1,770 times better than aluminum, 400 times better than steel, and 15 times better than masonry as an insulator, making it the most suitable material for decks.


Responsibly sourced timber is renewable since the forests will regrow. To tackle climate change effectively, we have to remove carbon from the atmosphere and reduce carbon emissions, both of which wood helps us achieve. Aside from encouraging greater interaction between people, exposure to wooden fittings and structures lowers heart rates and stress responses. Growing forests generate oxygen and further carbon storage.

Choosing Timber

Choosing Timber

In Australia, embodied carbon emissions produced by the construction sector accounted for approximately 20 percent of greenhouse gases. Aside from operational processes like transportation, considering the environmental effects of building materials is increasingly important. In addition to being the only renewable and naturally grown building material available, timber helps to remove greenhouse gases from the atmosphere.

Compared to other building materials, it takes a lot less energy to produce and process timber, which gives timber decks a significantly lower carbon footprint. Since processing the other building materials involves large amounts of fossil fuels, responsibly sourced wood is the best material.

Appearance, density, toughness, and durability are some of the factors considered when rating hardwood timber. Density rating is measured in kilograms per cubic meter and indicates the strength of the timber. The higher the mass, the denser the timber is. Durability is classified into four categories. Class-1 means high durability, resistance to decay, and a life expectancy of more than 40 years. Class-2 has a life expectancy of 25-40 years, class-3 has 7-15 years, and class-4 has 1-7 years. Toughness rating represents the impact resistance of timber. Although it’s measured in Newton meters, this rating is simplified to Low (0-15) Medium (15-25) and High (25 and above). Since the tests are performed only on unprocessed woods, timber can last a lot longer once treated, dried, painted, or stained.

Treated pine decks

When it comes to building timber decks, treated pine offers the best value for money. Thanks to the infused chemicals, treated pine is resistant to insect infestation and rot. As such, treated pine is ideal for decks installed in direct contact with the ground or in high humidity areas. In addition to being the least expensive decking material, treated pine takes paint, and stain finishes quite well. Since you can use any color or stain, treated pine decks offer an unmatched freedom of creativity. Aside from being readily available and cheap, the chemicals used might be less damaging than some of the staining and finishing products currently available on the market. While treated pine isn’t as dense or tough as most of the other materials, it is hard-wearing and can last for more than 40 years with proper maintenance. The fast growing nature of pine combined with the various chemicals used make this material more susceptible to temperature, moisture and humidity changes.


Treated pine requires a little more maintenance than the other wood. You may have to apply a lumber preservative because treated pine has not been treated against ageing, splitting, twisting, or swelling. Apart from needing regular staining and stripping, treated pine expands and contracts with climatic alterations. As a result, you may have to wet your deck in summer to prevent shrinkage and keep your deck from cupping, warping, cracking, swelling, or splitting.

Using a quality water and UV repellent product such as treated pine oil or paint greatly reduces the occurrence of such problems. However, treated pine needs to dry for at least three months before sealing or staining because the boards are usually damp when installed. When finished with a clear sealant, treated pine decks require minimal washing, sanding, and sealing.


Treated pine decks cost around $100 – $200 per square metre depending on factors such as density, size and location.

Hardwood decks

A wide range of hardwoods can be used for decks, and most of them are easy to work with. Aside from being aesthetically appealing and extremely durable when treated right, hardwood decks feel good underfoot and can bring nature right to your doorstep. However, it’s best to clean and re-stain your hardwood deck every two years to keep it in good shape, especially if you live in a wet or cold area.


As one of the most popular hardwoods for outdoor applications, Merbau comes from South East Asia. The attractive brown to yellow hue of freshly cut Merbau heartwood reddens with age, contrasting sharply with the white, pale-yellow, or buff colored sapwood. The sapwood is, however, susceptible to lyctid borer attack when left untreated. Although the grains can vary in appearance, they are usually interlocked or wavy and feature a coarse but even texture. Small yellow or gold flecks can be found throughout the wood. Merbau is considered the most beautiful timber for decks by many and consequently prized for its attractiveness.

Merbau has a durability class of 2, a toughness rating of M, and density rating of 850. In addition to this, Merbau is resistant to rot, insect infestation, and extreme weather. As a result, Merbau decks can last for more than 25 years with proper care. Merbau seasons quite well once kiln or air-dried, showing minimal signs of degradation and very little shrinkage or movement. Because of its exceptional density, minimal shrinkage, and unusual strength, Merbau is perfect for decks and provides optimal performance when used outdoors. Because it is extremely versatile, Merbau turns and responds well to hand tools, making it easy to work with and applicable to specific tasks like building timber decks.


Although Merbau has a tendency towards tannin bleed, it will finish well with polish, paint, and stain. The likelihood to gum bleed is not a long-term concern. If you are planning to install Merbau on or near surfaces that can stain, all you need to do is let it season elsewhere first. It is a low maintenance and eco-friendly.


Merbau hardwood decking is available at $150 – $250 per square metre depending on factors such as size and location.


This hardwood grows in the coastal parts of New South Wales and Queensland. With its straight or interlocking grains, consistent texture, and golden-yellow to pale brown heartwood, Blackbutt is aesthetically appealing. The sapwood is much lighter in appearance and not always easy to distinguish. Small gum veins might also be visible. Blackbutt has a toughness rating of M, a durability class of 2, and density rating of 900. It is strong, durable, versatile and highly fire resistant, making it perfect for decks, floors and joinery, particularly in bushfire prone areas.


Blackbutt has a tendency to surface check when drying and might crack if left unsealed. Fortunately, sealing Blackbutt immediately and oiling or staining on a regular basis might help. Blackbutt takes stain, paint and polish well even though the tendency to surface check might cause issues with painting. Blackbutt’s high extractives can stain painted surfaces when exposed to the weather. Although Blackbutt has little movement and machines well, it is not suitable for steam bending.


Blackbutt hardwood decking is available at $300 – $400 per square metre depending on factors such as size and location.


Jarrah is one of the most popular hardwoods Australia and is renowned for the rich browns and reds that deepen over time. The Jarrah tree (Eucalyptus marginata) grows in lateritic soils in parts of Western Australia. While the sapwood is pale yellow to pink-orange in color, the heartwood ranges from a deep brown to burgundy. Jarrah has a moderately coarse but evenly textured grain that when combined with the occurrence of wavy and interlocking patterns, produces the highly attractive fiddle-back figure; one of Jarrah’s most sought after features.

With a hardness of 8.5 and density rating of 800, Jarrah is renowned for its strength and ability to withstand time when used for outdoor applications. Besides being less susceptible to rot and insect infestation, Jarrah is fire-resistant and highly versatile. It is great for woodturning, which makes it ideal for weather resistant decks. Despite being a Class-3 timber for ground level use, Jarrah is a Class-1 wood for above ground applications and has a Class-2 durability rating.

In spite of its density, Jarrah is relatively easy to work with once seasoned, especially if the tools used are sharp. However, it is a lot easier to work with when green. But because of its density, extra care is necessary when using nails. When using a planer, setting the blade to 15 degrees gives the best surface quality. In addition to turning easily and responding well to machines, you can glue and steam bend Jarrah satisfactorily. Because Jarrah isn’t as oily as other hardwoods, you can sand it smooth and apply a clear finish. Jarrah readily accepts paint, stain and polish.


Jarrah requires more care and might be a little bit more expensive than the other options. You should seal this hardwood on all sides, provide adequate ventilation, and clean using caustic soda or products that contain oxalic. Once you have cleaned and rinsed your deck, allow the surface to dry before you finish it with specially formulated oil. Although Jarrah turns a pleasing shade of grey when left to weather, some products can restore its natural colors. Despite the maintenance work involved, many homeowners agree that Jarrah is worth the effort.


Jarrah decks cost $350 – $450 per square metre depending on factors such as size, availability and location.

Timber alternatives

Modular & Composite decking

When it comes to the construction of decks, there are several alternatives to wood. Unfortunately, some of them are falling out of favor. Composite decks, aluminum decks, and PVC or synthetic decks are the most common alternatives to wooden decks. Here is a deeper look at the alternatives.

Modular decks

As much as building a deck might be a rewarding experience, many people lack the skills and time it requires. As a result, a modular was created and was cost effective, easy to install, versatile, durable and aesthetically appealing.. Aside from having all the qualities mentioned above, modular decking kits do not have visible fixings.

In addition to providing the benefits of a modular system, it has a solid feel and appearance of well-designed and well-built decks. The installation of modular decks might be as much as five times faster than other decking systems. Additionally, the ease of installation does not compromise performance or durability. Modular decks have been designed to perform and last just as well as the other decking systems. In fact, this prefabricated system was specifically developed to prevent and fix some of the issues associated with composite and wooden decks.

Today, retailers offer modular kits in a variety of options including treated pine, popular hardwoods, plastic, and composite materials. Apart from being a quick and more affordable solution, most modular decking systems don’t need as much sub-floor clearance as self-supporting decks.

When it comes to traditional decks, one of the most frustrating aspects is that the installation process usually involves hundreds and sometimes thousands of screws. Thanks to these new and innovative systems, homeowners can add decks without the use of screws, glues, or alignment lines. Modular decks can be installed directly onto most surfaces. All you need to do is assemble the pre-fabricated frames, fit the supports, and adjust the heights before you insert the pre-fabricated deck panels. Use a concrete paver to ensure desirable aesthetic and technical results, especially when positioning over soft surfaces. Modular systems can provide a totally clean and aesthetically appealing surface.


Each kit requires a different level of maintenance, depending on the type of material used.


Modular decking systems are probably the cheapest option and can cost $50 – $150 per square metre.

Composite decks

Also known as PVC lumber, composite materials are playing a more significant role in decking than ever before. Even though it’s considered an alternative to timber, composite usually contains some wood. Most of the composite materials available are a blend of recycled plastic and wood fibers like sawdust and wood chips. The result is a board that offers an unmatched level of resistance to stains and extreme weather.

Although composite provides the same level of elegance as natural wood, it probably lacks the natural feel and beauty of real wood. Composite decks come in a broad range of colors, finishes and textures. As such, you can choose whatever suits your needs and preferences, non-slip surfaces included. Apart from requiring special fasteners, it is one of the most expensive decking materials currently available. However, composite decks are durable and extremely resistant to weather and stains.


Unlike wood, composite does not rot, splinter, warp, split, or shrink. Additionally, you can use every inch since it does not contain the inherent defects of wood. With no need for staining, sanding, or painting, composite decks require minimal maintenance. Despite being maintenance-free for the most part, it can be prone to mildew, which means you may have to spray it down occasionally.


Composite decks cost about $80 – $180 per square metre, depending on texture, strength, and weight among others.

Cost breakdown

Decking Costs


  • Timber decks cost approximately $100-$450 or more per sqaure metre depending on factors such as type, availability, aesthetic value, and location. However, treated pine is the least expensive of them all.
  • Composite decks cost between $50 – $150 per square metre, depending on texture, strength, and weight among others.
  • Modular systems are probably the cheapest option and can cost $80 – $180 per square metre.

Remember, the prices provided can vary depending on many different factors.

Which is right for you?

To make the process of choosing a deck a little bit easier, we have broken down and looked at each of the most popular choices in detail. This timber decks guide should help you determine which option meets your specific requirements the best. However, the cost, maintenance involved, geographical location, intended purpose, aesthetic value, and your personal preferences are all factors to consider when choosing your deck.


Since outdoor activities play a significant role in our lifestyles today, decks need to be as detailed and well-thought as interior designs. Decks are flexible and practical solutions that can help accommodate the needs of an outdoor-indoor family. Aside from maximizing unused yard space and transforming backyards into elegant entertaining areas, decks are worthwhile investments that can add to the value of your property.