Composite Decking vs Merbau

Key information

• Merbau is a popular tropical hardwood in Australia, valued for its rich reddish-brown colour and natural durability.
• Merbau is slow to regrow, so responsible sourcing matters; FSC-certified options are available.
• Merbau needs regular oiling to hold its colour, and fresh boards can bleed tannins that stain nearby surfaces.
• NexGEN composite decking offers a very low maintenance alternative. Select Jarrah colour is the closest match to merbau, backed by a 50-year stain and fade warranty.

Merbau (also known as kwila) is easily identified by its rich, warm brown hue which reddens with age. As hardwood goes, it is a popular one in the Australian market – often positioned as a desirable, premium option with natural durability.

These days, there are alternatives to hardwood for a hard-working deck. Premium composite decking can offer long-lasting durability with much less maintenance over time – particularly in comparison to an oily wood like merbau, which requires regular cleaning and re-oiling or staining every 6-12 months (depending on exposure and the desired appearance) to retain the iconic rich colour.

Quick comparison table: Composite decking vs merbau

Why merbau became a natural timber decking favourite

Sourced from Southeast Asia and other tropical regions including Northern Queensland, merbau is prized for its beauty and relative durability. It has a beautiful rich tone and is naturally resistant to many pests – more so than softer options like pine, for instance. With these qualities can come some trade-offs; if you’re a homeowner looking to create a beautiful and long-lasting outdoor space, you should carefully consider whether merbau is the right material for you.

Is merbau a sustainable material?

Hardwood is slow to grow, and merbau is no exception. Regrowth takes decades, and in many regions, harvesting has outpaced it.

There are responsible ways of sourcing merbau; for example, FSC-certified merbau is harvested from responsibly managed forests. However, high global demand has contributed to unsustainable logging practices and illegal harvesting in some tropical forests. If you choose merbau, it’s worth asking your supplier about certification and where the timber comes from.

How will merbau perform as your new deck?

If you are looking to DIY a deck, merbau will require good-quality tools; it is dense and can be hard to cut. It also requires a bit of elbow grease to keep it looking beautiful long-term. Colour upkeep is often one of the more challenging parts of merbau decking, which will weather silver-grey if left to its own devices.

The inherent oiliness of the timber makes it relatively durable against moisture, cracking, decay and insects like termites. Being a tropical hardwood, it’s able to withstand the heat, sun and humidity of many Australian applications.

If you have ever had a merbau deck, you are likely familiar with a much-bemoaned downside of having this rich wood up against your house: the tannins. While this should reduce over time, fresh merbau is prone to leaving reddish-brown staining on concrete, pavers, tiles and render – especially after rain, and especially in the first few months. If you choose merbau, you will need to stay on top of this so fresh stains don’t set in.

A common recommendation is pre-weathering, which is when you leave the merbau outdoors and exposed for 4-8 weeks while regularly hosing it down to accelerate the release of tannins before using the timbers to build a deck. This means a fair amount of time and effort on maintenance before you have even built the structure.

How premium capped composite compares to merbau

Environmental impact of composite decking products

This can vary between brands. NexGEN capped composite is made from 50% hardwood fibre and 50% UV-stabilised, high-density polyethylene; this is engineered from reclaimed wood fibres and recycled plastic, diverting waste from materials that were once headed to landfill. This extremely durable combination stands up to the often-extreme conditions in Australia, looking great year after year even in decking projects for full sun.

By using reclaimed and recycled materials, NexGEN PermaTech® composite boards offer an alternative to relying on newly harvested timber.

Related: Composite Decking vs PVC Decking: Which is Right for You?

Installation and maintenance requirements

Unlike merbau, NexGEN composite decking is very low maintenance. Our PermaTech® boards can be cut with standard woodworking tools and fixed with concealed fasteners. Installation must follow the relevant NexGEN and Fiberon installation requirements; learn about the overall process in our guide to building a low profile deck.

Everyday cleaning is as easy as a quick sweep, plus the occasional scrub with soapy water and a broom for any sticky spills or heavier surface debris. PermaTech® boards are highly fade- and stain-resistant, and they don’t need oiling or sanding.

Cost considerations: Merbau vs composite decking

Merbau is considered a more premium hardwood, and as such the price isn’t drastically cheaper than premium composite decking. Over time, however, high-quality composite decking can be more cost-effective. This is because:

• NexGEN composite decking offers more peace of mind in the long-term, even against durable hardwood decking like merbau. NexGEN’s Select range has an industry-first 50-year stain and fade warranty, and a lifetime limited structural guarantee for residential use.
• You can save money and time on regular maintenance; spend your weekends doing what you want, instead of maintaining the visual appeal of your decking project.

It is well worth calculating price beyond your initial spend per square metre of material. For homeowners who value reduced ongoing maintenance, composite decking can offer compelling long-term value.

Choosing the right decking material for your needs

Is there a way to get the merbau look from composite decking? Again, that depends on what kind of composite you select. Some brands have more convincing wood grains and hues than others. NexGEN’s Select range is specially designed with no visible repeats or easy-to-discern patterns, is completely reversible, and offers convincing multi-chromatic colours in natural Australian wood hues.

From our range, we would recommend Select Jarrah as the closest match for merbau’s characteristic rich, reddish tones. Ironbark from our Promenade PVC range is also a close match, with a similar red-brown tone. You can achieve the natural timber look you want, without the oiling and tannin staining that come with merbau – just take a look at these swatches:

*Colours shown are indicative only — actual product colour may vary due to lighting, screen settings, and natural batch variation.

Related: Composite Decking Colours 101: Everything You Need to Know!

Built to withstand Australian conditions year after year

While merbau has plenty of desirable qualities for timber, PermaTech® capped composite decking offers extremely durable, long-lasting good looks without the risk of natural timber tannins staining your home. Skip the regular oiling and choose premium composite decking made from reclaimed wood fibre and recycled plastic. Curious about the cost? Try our composite decking price calculator for a free estimate.

If you would like to see how our product would look in your home, simply request a free sample today using the form below. We ship anywhere in Australia so you can see your options in your own natural light, next to your existing colour scheme, before you buy. Need help deciding which NexGEN product is right for your decking project? Why not contact our team today – we are always happy to offer advice.