How to Choose the Right Merbau Decking Finish for Australian Weather

There’s this moment—late afternoon. The sun dips low, catching the edge of your deck just right — and suddenly, that Merbau decking by GreenHill Timber glows like it’s alive. You can almost hear the timber sigh. A quiet creak. A whisper of warmth.

That’s the beauty of Merbau. It’s not just timber. It’s a feeling. It carries the smell of rain, the weight of summer, the sound of bare feet crossing to grab one more drink before dinner.

But here’s the thing most people forget: that glow doesn’t keep itself. Australian weather can be a bully — too much sun, too much rain, too much salt in the air. Even Merbau, that famously tough tropical hardwood, needs a bit of help staying beautiful.

And that’s where the finish comes in.

The Weather Doesn’t Care About Your Deck

You can love your Merbau decking, sure. You can oil it, sweep it, host a dozen barbecues on it. But the weather? It doesn’t care.

One week, your deck’s basking in sunshine. Next, it’s getting drenched by sideways rain. If you live near the coast, the salt air seeps into every joint. In the outback, the dry heat can pull the moisture right out of the boards.

That’s why the finish matters. It’s not just about shine — it’s about survival.

Oiling: Like Giving Your Deck a Drink

Something is soothing about oiling timber. The way the colour deepens as the oil sinks in, how the surface darkens and glows, like watching the wood come back to life.

For Merbau decking, oiling is the old faithful. It’s simple, natural, and lets the grain stay front and centre. There are two kinds — the deep-penetrating type that soaks in, and the film-forming one that sits up top.

If your deck spends most of its life under full sun, go for penetrating oil. It moves with the wood — breathes with it. If you prefer a glossy, more polished look, the film-forming kind might be your thing.

Just don’t rush it. Thin coats, always. Let it sink. Wipe the excess. Stand back. Smile a little.

Because when oil hits Merbau decking, it’s like fire meeting earth. A quiet kind of magic.

Staining: When You Want a Little More Drama

Some decks whisper. Others want to be seen. If you’re leaning toward the latter, staining is your move.

Stains do more than change colour — they tell a story. A deep chocolate stain gives your deck a moody, modern edge. A lighter amber tone? Feels coastal, breezy, barefoot.

But timing is everything. Merbau bleeds tannins — that reddish-brown pigment that leaks out when it rains. If you stain too early, the tannins get trapped under the finish, and your hard work goes blotchy.

So be patient. Let the timber settle, wash it down, let it bleed, then start. Decks are like people — they need time to breathe before they’re ready for a makeover.

Sealing: The Invisible Hero

A sealant doesn’t get much glory, but it deserves it, especially if your home sits near the ocean or anywhere damp.

Sealing your Merbau decking keeps out the water, stops swelling, and prevents rot before it even starts. It’s like invisible armour. You don’t see it — you just see your deck stay beautiful long after it should’ve started showing its age.

You can even find combo products now — oil and seal in one. Just be careful. Some all-in-one promises do neither job properly. Read the label. Or better yet, talk to someone who’s been doing decks longer than you’ve been thinking about it.

What Works Where (Because Australia’s a Mixed Bag)

Let’s be honest — there’s no “one size fits all” here. What works in Perth might fail miserably in Cairns.

• Coastal homes: Penetrating oil with UV protection and anti-mould. Salt is your enemy.
• Tropical climates: Seal it up tight. The humidity here is no joke.
• Dry inland areas: Oil regularly. Keep that timber hydrated.
• Down south: Less sun, more moisture — anti-mould is key.

You get the idea. Your postcode decides your plan more than the can of oil ever will.

A Few Truths Nobody Tells You

• Don’t oil at noon. The heat dries it before it even sinks in.
• Don’t go heavy on the coat. It’ll just turn tacky.
• Stir, always. Pigment settles — you’ll thank yourself later.
• Test on a scrap board first. Every piece of Merbau decking is its own creature.

These are the quiet lessons you learn after a few weekends of trial, error, and muttered cursing.

When It’s All Done Right

Here’s the reward: that first morning after you’ve finished. The deck’s still slightly warm from yesterday’s sun, the oil’s cured overnight, and the grain glows like embers.

You run a hand over it. Smooth, solid, alive. You think — yeah, that was worth it.

Because when you take care of Merbau decking from Green Hill Timbers, it gives back. It doesn’t just hold up your furniture or frame your afternoons — it becomes part of the rhythm of the house. The place where summer happens. Where the dog naps. Where conversations stretch long after the food’s gone cold.

And that finish you chose? It’s the quiet hero holding it all together.

So oil is slow. Stain with purpose. Seal, like you mean it.
Your deck will remember.