Design Your Dream Deck: How 140mm Merbau Can Elevate Your Outdoor Space

When dreaming of the perfect outdoor living area, the choice of decking material is the single most important decision you’ll make. It dictates the look, feel, durability, and ultimately, the enjoyment of your space. While many timbers vie for attention, Merbau Decking stands out as a global favourite, renowned for its rich colour and exceptional resilience. But to truly maximize visual impact and create a luxurious feel, you need to consider the width of the boards—specifically, the generous 140mm Merbau decking.

This comprehensive guide explores why Merbau timber decking is a prime choice for any climate and how opting for the wide 140mm Merbau decking board dimension can dramatically elevate your backyard into a sophisticated, high-impact sanctuary.

Why Merbau Decking is a Global Hardwood Star

Merbau (Intsia bijuga) is a tropical hardwood sourced primarily from Southeast Asia. It has earned its reputation as a premium decking material due to a combination of aesthetic and structural advantages.

1. A Colour That Radiates Warmth

Merbau is perhaps best known for its stunning, deep colour palette. When freshly cut, it boasts a vibrant golden-brown to reddish-brown hue. Over time, and with the application of quality decking oil, this colour deepens into a rich, luxurious mahogany or dark reddish-brown, creating a warm, inviting atmosphere that is perfect for outdoor entertaining. This aesthetic richness is a significant reason why many choose a Merbau deck.

2. Exceptional Durability and Longevity

Merbau is classified as a Durability Class 1 timber, which distinguishes it as one of the most resilient natural timbers. This classification indicates that it is anticipated to have a lifespan of more than 40 years when installed accurately above ground. Its natural lipids and high density offer the following:

• Termite and Pest Resistance: The natural compounds within the timber repel most common wood-boring insects.
• Rot and Decay Resistance: It handles moisture extremely well, making it suitable for areas exposed to rain, humidity, and pool surrounds.
• Stability: Merbau is known for its excellent stability, resisting warping, twisting, and cracking better than many other woods.

3. Low Maintenance

While all decking requires some maintenance, the natural oils in Merbau decking timber mean it is naturally protected. Routine cleaning and an annual or bi-annual coat of decking oil are typically all that’s required to maintain its rich colour and structural integrity.

The Wide Difference: Why Choose 140mm Merbau Decking

While 90mm Merbau decking is the traditional standard width, the growing trend in contemporary design is toward wider boards. Opting for the 140mm Merbau decking (commonly available as Merbau decking 140 x 19) offers numerous design and practical advantages that can transform an ordinary deck into a magnificent one.

1. A Grand, Expansive Aesthetic

The wider 140 Merbau decking boards create an immediate sense of scale, luxury, and solidity.

• Fewer Lines, More Flow: Wide boards reduce the number of visible gaps and joins, creating a smoother, cleaner surface. This continuous flow makes the entire deck area appear larger and more expansive—an optical illusion that is especially effective in smaller or average-sized backyards.
• Modern Sophistication:Wide boards align perfectly with modern architectural trends, which favour clean lines, minimalism, and broad, unbroken surfaces. A deck with 140mm Merbau decking instantly looks higher-end and more custom-designed.

2. Showcasing the Timber’s Beauty

Merbau’s signature feature is its rich colour and often interlocked grain pattern. A wider board provides a larger canvas to showcase these natural characteristics. The depth of the colour variation and the beauty of the timber’s unique grain are more apparent on a 140mm board than on a narrower 90mm one.

3. Reduced Installation Time

In a strictly practical sense, the use of 140mm merbau decking boards results in a reduction in the number of boards necessary to cover the same area as 90mm boards. This translates directly to:

• Fewer Fasteners: Less drilling and fewer screws are needed.
• Less Labour: The reduced number of boards significantly cuts down on overall installation time, potentially leading to lower labour costs for your builder.

Designing with 140mm Merbau: Tips for a High-End Finish

To ensure your wide Merbau deck achieves its full potential, consider these design and installation details:

1. Optimal Fastening Strategy

With wider boards, minimizing movement is key to maintaining stability.

• Hidden Fixings: Consider a concealed fastening system for a high-end, seamless appearance that fully leverages the board’s width. The boards are secured by these systems from the side or underneath, resulting in a pristine surface that is free of visible fasteners.
• Screws: If using traditional face-screwing, ensure high-quality stainless steel screws are used and consider placing two screws every 400-450mm to minimize any potential cupping or movement across the wide surface.

2. Managing the Tannins (The “Bleeding” Factor)

Merbau is famous for its high content of natural tannins (oils), which are responsible for its durability and rich colour. However, when first exposed to rain and moisture, these tannins can leach out, causing reddish-brown “bleeding” that can stain concrete, paving, or pool surrounds.

• Pre-Washing is Essential: Before installation or immediately after, the boards should be thoroughly pre-washed or “de-tannined” using a specialized decking cleaner. This process helps to leach out the surface tannins and stabilize the timber, preventing staining on the surrounding areas.
• Protect Adjacent Surfaces: During the pre-wash phase, cover all surrounding masonry or paving to catch the runoff.

3. Choosing the Perfect Oil

The final finish will define the deck’s aesthetic.

• Maintaining the Colour: Use an oil with a Merbau tint or a reddish-brown pigment. This will enrich the natural colour and provide the highest level of UV protection, slowing down the silvering process.
• Allowing to Silver: If you prefer the low-maintenance, weathered look, you can allow the timber to silver naturally. However, it’s still advisable to use a clear protective coating> that nourishes the wood and prevents surface cracking, even if you want the colour to fade.

The True Value of a 140mm Merbau Deck

The investment in a high-quality, wide-board Merbau deck offers superior long-term value, despite the modest increase in initial prices compared to standard softwoods or specific composites.

The combined factors of its Durability Class 1 rating, its exceptional stability in variable climates, and the luxurious, expansive look provided by the 140mm Merbau decking boards mean you are building a feature that will last for decades with minimal fuss. Your Merbau deck won’t just be an outdoor space; it will be a durable, high-impact extension of your home’s living area.

By choosing Merbau timber decking and opting for the wide 140mm profile, you are designing a deck that is aesthetically stunning, structurally sound, and perfectly tailored for a lifetime of outdoor enjoyment.

Ready to transform your space with quality that lasts? Explore the range at Melbourne Timber Supplies—your go-to source for Hardwood Decking in Australia.

Frequently Asked Questions (FAQ)

• Q. Why choose 140mm Merbau decking over the standard 90mm?
  The 140mm Merbau decking creates a more luxurious and contemporary look by reducing the number of board joints, which makes the entire deck surface appear wider, smoother, and more expansive. It also showcases the rich colour and unique grain of the timber on a larger canvas.
• Q. Is Merbau decking fire resistant?
  Merbau is generally considered one of the more fire-resistant tropical hardwoods due to its high density, though its specific fire rating (like the Australian BAL rating) can vary. Always check with your supplier and local building codes if you are in a high-risk area.
• Q. What is “bleeding” and how do I prevent it from staining my paving?
  “Bleeding” is when the natural tannins in Merbau decking timber leach out when exposed to moisture, which can leave a reddish-brown stain on surrounding surfaces. To prevent this, the boards must be thoroughly pre-washed or de-tannined with a specialized deck cleaner before or immediately after installation.
• Q. How often should I oil my Merbau deck?
  To best maintain the rich colour and provide optimal UV protection, it is generally recommended to apply a quality decking oil (ideally with a Merbau tint) annually or every 18 months, depending on your deck’s exposure to direct sunlight and weather.
• Q. Is Merbau a sustainable choice for decking?
  In order to ensure that the timber is sourced from legally and sustainably managed forests, it is essential to purchase Merbau decking from suppliers who provide certification (such as FSC or equivalent). This guarantees the timber resource’s long-term sustainability.