Best Timber for Decking in Australia: Top Choices & Expert Tips

As Australians, we love the outdoors, and it’s no secret that outdoor living is a big part of our lifestyle. Weekend get-togethers, lazy summer afternoons, and spending time with family and friends all feel better when enjoyed on a well-designed deck!

But with so many timber options available, how do you choose the right one?

At Gowan Lea Timbers, we’ve proudly helped clients across Brisbane and the Sunshine Coast find the best timber decking solutions to suit their needs, style, and budget. From rich, durable hardwoods to more budget-friendly solutions and even the latest in timber technology, there’s a decking option for every home and lifestyle.

In this post, we’ll walk you through the top timber choices for decking in Australia, what to consider before making your decision, and expert tips to help you get the most out of your deck, now and in the future.

Why the Right Decking Timber Matters

Australia’s climate can be tough. Scorching sun, heavy rain, high humidity, and sudden temperature shifts can all take a serious toll on outdoor materials, especially timber decking. That’s why choosing the right timber is so important. It’s not just a design decision (though that’s important too!) This ensures your outdoor space will stand strong against the elements, helping protect your outdoor space for as long as you use it.

Understanding Timber Ratings

Not all timber materials are made the same. Some are more suitable for high-traffic areas, others excel in moisture resistance, and certain species offer better fire protection. Understanding how timber is rated for durability, hardness, fire resistance, and appearance can help you choose the right option for your specific needs and environment.

Durability Classes

Timber is categorised by its natural resistance to decay:

• Class 1: Very high durability and can last 40+ years above ground (e.g. Ironbark)
• Class 2: High durability and can last 15 to 40 years (e.g. Blackbutt)
• Class 3: Moderate durability and can last 7 to 15 years (e.g. Stringybark)
•  Class 4: Low durability and can last 1 to 7 years (best for temporary structures)

Fire Resistance (BAL Rating)

Bushfire Attack Level (BAL) ratings refer to the level of fire resistance a material has. This means how well a particular timber can withstand exposure to bushfires, including radiant heat, ember attack, and direct flame contact. If you live in a bushfire-prone area, choosing a decking timber with a suitable BAL rating is crucial for meeting safety standards and protecting your home.

• BAL Low: Lowest risk from a fire.
• BAL 12.5: Risk from embers.
• BAL 19: Moderate risk from embers and debris.
• BAL 29: High risk from embers, debris, and heat.
• BAL 40: Very high risk, including flames.
• BAL FZ: Extreme risk, directly exposed to flames.

Timber Appearance Grades

While strength and durability are critical factors when choosing decking timber, appearance also plays a big role, especially if you’re after a certain look or want your deck to complement your home’s overall style.

Timber is a naturally beautiful material, and different appearance grades allow you to choose just how much character or uniformity you’d like to see in your boards.

• Select Grade: Select grade timber offers a clean, minimal look with a uniform grain and very few natural imperfections. This type of timber features minimal knots, gum veins, or variations.
• Standard Grade: Standard grade timber features a more varied and natural appearance than select grade. You’ll notice a moderate amount of knots, burls, gum veins, and other natural characteristics throughout the boards. These features give the timber a bit more personality while still maintaining a fairly consistent and balanced look.
• Natural or Feature Grade: Feature grade timber is full of character and charm. Expect prominent gum veins, insect trails, face checking, and other visible markings that make the timber unique. This grade is ideal for creating a rustic, earthy, or more traditional look.

The Best Timber For Decking

When it comes to building the perfect outdoor deck, we are spoilt for choice. There is an option for every need, budget and lifestyle. Some of the most common decking timber materials include:

Hardwoods

Hardwood decking is a favourite among Australian homeowners and builders for its durability, natural charm, and high-performance qualities in harsh conditions. Let’s take a look at some standout hardwood varieties:

Ironbark

Ironbark is one of Australia’s toughest native hardwoods, boasting a Class 1 durability rating. With a lifespan exceeding 50 years in protected areas(and even longer with proper care), this timber can endure the toughest conditions.

• Colour: ranges from pale brown to deep red and chocolate, with an interlocked grain pattern that gives it a unique texture.
• Pros: Highly durable, resistant to termites, and fire-resistant
• Ideal for: Bushfire-prone areas and those seeking low-maintenance, long-lasting timber

Spotted Gum

This is one of the most commonly used Australian hardwoods. Spotted Gum is known for its strength, and if left untreated, it develops an attractive silver-grey patina over time.

• Colour: A mix of pale creams to deep chocolate browns that goes silver-grave over time.
• Pros: Fire-resistant, low tannin content, great for staining and oiling
• Ideal for: Areas that require durability, fire resistance, and aesthetic appeal

Merbau

Also known as Kwila timber, Merbau is a tropical hardwood that’s incredibly popular thanks to its stunning appearance and robust performance. Although it comes at a slightly higher upfront cost, Merbau’s natural resistance to moisture, decay, and insects makes it well worth the investment for long-term outdoor use. It’s especially ideal in climates with high humidity or heavy rainfall.

• Colour: Reddish-brown finish and an interlocking grain pattern.
• Pros: Resistant to moisture, cracking, decay, and insects
• Ideal for: Areas exposed to harsh weather, moisture, and frequent use

Jarrah

Native to southwest Western Australia, Jarrah is a premium hardwood known for its deep, rich colouring and natural resistance to the elements. It has a Class 2 durability rating, which means it can last up to 25 years above ground with proper maintenance.

• Colour: It has rich tones that range form light red to deep burgundy.
• Pros: Natural oils resist rot, fungi, and termites; bushfire-resistant
• Ideal for: Pool and spa decking, and bushfire-prone areas

Blackbutt

Blackbutt is a strong, reliable, and sustainable Australian hardwood that’s particularly popular in decking projects across southern Queensland and New South Wales. With a Class 1 durability rating, it offers long-lasting performance outdoors, and its attractive appearance makes it a designer favourite. It’s also one of the few native timbers approved for use in bushfire-prone areas due to its fire-resistant properties.

• Colour: Pale brown to golden yellow hues, with a fine, straight grain.
• Pros: Fire-resistant, beautiful finish, and great for staining
• Ideal for: Bushfire-prone areas and large outdoor projects

Treated Pine

For those working on a budget, treated pine provides a cost-effective solution without sacrificing too much quality. his widely available softwood is chemically treated to improve its resistance to decay, insects, and the harsh Australian elements, making it a practical and affordable choice for outdoor applications.

Treated pine is the most affordable decking option available, and its adaptability makes it perfect for DIY projects. Plus, it’s easy to work with. This softwood can be cut, drilled, and installed without the need for specialised tools, which is why it’s a favourite among DIY enthusiasts and those looking to save on labour costs.

• Colour: Pale yellow to light green (due to treatment); easily stained or painted to suit any style
• Pros: Affordable, customizable through staining or painting, easy to work with
• Cons: Treated pine does come with trade-offs. It requires more regular maintenance than hardwoods, susceptible to scratches and dents
• Ideal for: Budget-conscious homeowners or temporary decking projects

Composite Decking

For a modern, low-maintenance alternative to timber, composite decking is a fantastic choice. Made from a blend of recycled plastic and wood fibres, it offers the aesthetic appeal of natural timber with the added benefit of enhanced durability and minimal upkeep.

Composite decking is designed to resist the common issues that timber faces, such as warping, splintering, rotting, and insect damage, making it an ideal choice for homeowners who want to enjoy their outdoor space without the hassle of regular maintenance.

While composite decking requires a bigger initial investment compared to traditional timber, it offers long-term savings. You won’t need to spend time or money on regular maintenance tasks like sanding, staining, or sealing.

A simple wash with soap and water is usually all it takes to keep it looking great year after year. This makes it an excellent option for busy homeowners looking for a hassle-free outdoor solution that still delivers the beautiful, natural look of wood

Accoya Timber Decking

If you haven’t heard of Accoya® before, you’re not alone. While still relatively new to the Australian market, it’s quickly becoming a popular choice for both DIY enthusiasts and professionals alike. But what exactly is Accoya® Timber?

Accoya® isn’t a type of tree, but rather the brand name for a high-performance modified wood that is made from a fast-growing radiata pine that is grown in sustainably managed forests. Once harvested, the raw pine timber undergoes a process called acetylation. Here, the timber is treated with acetic acid to alter the wood at a molecular level, creating a product that is stable, durable, and resistant to common issues like rotting, warping, swelling, and shrinking.

• Colour: Accoya® starts with the light, creamy tones of traditional pine. It naturally weathers to a stunning silvery-grey finish over time.

• Durability: Rated Class 1 for durability, meaning it’s built to last in even the toughest conditions. It’s highly stable across different climates, resisting rot, decay, and warping.

• Pros: Accoya® is incredibly durable, dimensionally stable, and naturally resistant to rot, moisture, and termites. It won’t warp, swell, or splinter, requires minimal maintenance, making it a sustainable, non-toxic choice that performs beautifully in even the harshest environments.

 

Did you know? Gowan Lean Timbers has proudly supplied Accoya for the 400-metre-long Noosa Boardwalk as part of the $7 million refurbishment project by Hutchinson Builders. While the sub-frame featured locally sourced and treated Spotted Gum and Ironbark from our Mary Valley sawmill, the decking itself was built using the ultra-modern Accoya, chosen for its exceptional durability, stability, and resistance to the coastal elements. 

Tips For Choosing The Best Decking Timber

There are a lot of factors that go into choosing the right timber decking material. These include:

1. Budget

Your budget will naturally shape your options. If you’re working within a tighter range, treated pine is a great cost-effective choice. It’s one of the most affordable decking timber materials and ideal for larger projects. On the other hand, premium hardwoods like Merbau and Jarrah may cost more upfront, but make up for the investment in longevity, strength, and visual appeal.

Tip: Always get several quotes to compare pricing and quality. Spending a little more for better materials can save you money on repairs or replacements down the track.

2. Size, Location & Usage

The size and layout of your deck affect how much timber you’ll need and the overall cost. It’s also important to consider how and where your deck will be used:

• Bushfire-prone areas: Choose bushfire-resistant timbers (compliant with AS 3959-2009)
• Humid climates: Opt for timber that is resistant to warping and shrinkage
• Near pools or water: The chosen timber needs to handle moisture and chemicals well to prevent damage and ensure longevity.
• High-traffic areas: Opt for dense hardwoods for added strength and durability

3. Aesthetic Appeal

You’ll be spending a lot of time outdoors, so your deck should look the part! In addition to durability, timber types vary widely in colour and grain. This allows you to choose a timber that best suits your aesthetic needs. Timber can also be enhanced and altered with oils, paints and stains. Also, consider board width. Narrow boards create a more traditional look, while wider boards feel more modern and spacious.

4. Maintenance Requirements

All timber decks need some TLC, but the level of maintenance can vary depending on the material. Hardwoods generally require less upkeep than softwoods, but regular care will keep any deck looking great.

Check your deck at least twice a year and give it a thorough cleaning to remove dirt, debris, and mildew. How often you oil the timber depends on sun exposure; sun-drenched areas may need oiling several times a year, while shaded areas might only need one coat annually.

5. Durability & Weather Resistance

Australia’s weather can all take a toll on the appearance and durability of your deck. So, it’s important to choose timber that can stand up to the elements.

Look for timbers with high durability ratings, like Ironbark (Class 1), Blackbutt, and Spotted Gum. Merbau is also highly durable thanks to its natural oils, which help prevent cracking, rot and insect damage.

Dense timbers absorb and release moisture more slowly, meaning less warping and shrinking over time and keeping your deck looking better for longer.

6. Sustainability

Sustainability matters more than ever. Many people are opting for more sustainable building practices, and that extends to decking too. Sustainable timber is sourced from well-managed forests, ensuring that trees continue to grow while minimising environmental impact.

Look for these eco-certifications:

• Good Environmental Choice Australia (GECA)
• Eco Select
• Forest Stewardship Council (FSC)
• WWF Global Forest & Trade Network
• PEFC (Program for the Endorsement of Forest Certification)

Sourcing local timber also helps reduce carbon emissions from transport. Alternatively, composite decking made from recycled materials is another eco-friendly option that’s low-maintenance and helps divert waste from landfills.

How To Care For Decking Timber?

Your deck is an investment, and like anything exposed to the elements, it needs a little ongoing care to stay looking its best. Whether you’ve chosen a rich, durable hardwood or a more budget-friendly softwood like treated pine, regular maintenance is key to preserving its beauty and extending its lifespan.

• Regular Cleaning: Organic matter left to sit can break down and become acidic, which may stain or slowly degrade the timber. A consistent cleaning routine will remove any loose leaves, dirt and debris that may damage your deck. Before cleaning, it’s best to remove all furniture and outdoor items. Begin with a thorough sweep using a stiff broom, then move on to cleaning any built-up grime. Depending on the type of timber, you may need to use a gentle cleaning solution.
• Pressure Washing: Some dirt and grime are stubborn and difficult to remove with regular cleaning. Pressure washing is another effective way to remove deep-seated dirt and mildew, but it must be done carefully to avoid damaging the surface. Use a lower pressure setting and work in long, even strokes that follow the direction of the grain. Be sure to test the pressure on a hidden section of your deck to be safe.
• Oiling, Sanding or Painting: To maintain your deck’s protection against moisture, UV rays, and daily wear, it’s recommended to re-oil, paint, or reseal the surface every 12 to 24 months. Make sure your deck is thoroughly clean and completely dry beforehand. If your timber is weathered or rough, a light sanding can help rejuvenate the surface don’t forget to reseal it afterwards!

Ready To Make Your Pick?

Ultimately, your choice will depend on your specific needs, the climate in your area, and how much time you’re willing to invest in upkeep. Whether you’re looking for durability, aesthetic appeal, or ease of maintenance, there’s a decking option that’s perfect for your project and budget.

High-end hardwoods like Ironbark and Spotted Gum last an incredibly long time but come with a steeper price tag. Treated pine works well for budget-friendly projects, and composite decking and modified timber is perfect for homeowners who want less maintenance work without compromising on the look of traditional timber.

Ready to start your decking project? Visit Gowan Lea Timbers, an award-winning supplier on the Sunshine Coast. With 25 years of expertise, we provide top-quality decking timber, from hardwoods like Ironbark and Merbau to composite options. Builders, architects, and DIY enthusiasts trust our knowledge and service for decking projects.

Reach out to us today to find the perfect materials for your next build!