The Kiwi Homeowner’s Guide To Kwila Deck Maintenance

A Kwila deck is a beautiful and valuable asset to any home and can be the perfect backdrop for summer barbecues, family gatherings, or just some quiet downtime. Decks built using Kwila increase a property’s value as it’s a premium hardwood timber renowned for its durability and high density.

But your Kwila deck needs regular maintenance and care to stand against New Zealand’s challenging weather conditions. Dryden Woodcare products are made especially for NZ conditions and make Kwila maintenance easy and stress-free. This is a comprehensive roadmap to Kwila deck maintenance around the home, covering everything from cleaning, staining and restoring Kwila.

Kwila Decking

Kwila, also known as Merbau, is a richly-dark timber that is a high quality, strong and durable hardwood. Because it can handle harsh climates and is naturally resistant to both boring insects and fungal rotting, Kwila is a popular decking material in New Zealand.

But, Kwila decking faces some tough challenges- long-term exposure to UV rays, rain and heat can deteriorate your Kwila deck and make the once beautiful timber fade or distort with these common issues:

  • Cupping
  • Weathering
  • Splitting
  • Discolouration
  • Silvering
  • Moisture retention

The solution? Dryden OilStain! This is a deeply penetrating oil that nourishes most exterior timber species, including Kwila. It helps prevent all of the above-mentioned issues and extends the lifespan of your Kwila decking if treated and maintained properly.
To give your Kwila extra UV protection, add Colourtone+ to Dryden OilStain.


Best Kwila Maintenance Products for NZ Conditions

Dryden offers some of the best timber maintenance products, including premium-grade Kwila decking oil, stains and cleaners.

Specially made for New Zealand conditions, these wood care products are designed to help protect and enhance the natural beauty of your Kwila decking. You can easily find them at your local hardware or DIY store.

How Do You Maintain A Kwila Deck? Seal And Protect Your Kwila From Its Biggest Enemy

Moisture is the biggest enemy of Kwila decking. That’s why we created Dryden OilStain, a deeply penetrating, water-resistant oil that nourishes and protects the Kwila timber from within to help it last longer.

To protect your deck from NZ’s harsh sun, add Dryden Colourtone+, which provides colour to Dyden OilStain and comes in over 37 colours.



What’s your current coating?

If your Kwila decking is brand new or already coated with a deeply penetrating oil, Dryden OilStain will be a premium choice for maintenance.

If it’s got a traditional oil-based stain, use Cabots Deck & Exterior Oil-Based.

If water-based stain, then Cabot’s Water Based Deck and Exterior Stain or Intergrain Ultradeck Timber Stain.

Dryden OilStain makes Kwila deck maintenance easy and effortless! There’s no need for fancy equipment -use any standard brush or speed pad (just not lambskin ones!) to apply.

Professionals can also use a roller or spray gun, but everyone gets a great-looking and long-lasting result!


How to Identify the Coating on Your Decking

#1 Do a solvent resistance test – The most common way to identify the type of coating is through solvent resistance tests. For example, if a water-based stain is treated with methylated spirits, it will quickly become gummy and sticky.

#2 Check appearance – To check if the coating is a film-forming stain, look at its appearance – if it looks shiny or plastic, or if it’s flaking, then it’s likely a film-forming stain.

#3 Do a burnish/dry rub test – For migrating oil stains, you can do a simple burnish/dry rub test with a clean rag to see how easily the pigment is removed. If the pigment comes off easily, this suggests a migrating stain was used.

However, please note that all the above methods are indicative only and not foolproof. So, to accurately identify the coating on your cladding, it’s better to talk to a professional.

Pick The Best Colour For Your Kwila Stain

Adding colour to your Kwila decking is simple and straightforward with Dryden Colourtone+, which comes with over 37 shades to choose from.

It helps provide UV protection to your Kwila deck while complementing its colour and character without hiding the grain.


*Will silver as product weathers overtime


*Will silver as product weathers overtime


Lite Oak










Weathered Cedar



Silver Grey







Black Teak













Soft Grey


Dryden OilStain colours and finishes shown here are representative only. The colour you choose and the amount of oil applied may change the final achieved colour.

How To Choose A Kwila Stain And Apply It

One of the best stains for a Kwila deck is a transparent wood stain, as it brings out the beautiful, natural grain of Kwila. The combination of Dryden OilStain and ColourTone+ makes the perfect combination.

Dryden OilStain and ColourTone+ work together to prevent Kwila from cracking or flaking by nourishing and protecting the timber from within. This combination is also used to add colour to the timber while protecting it from harmful UV rays.

Remember to use the same colour throughout the application so your Kwila decking maintains a consistent look.

Using multiple cans? Mix them together to keep the same tone throughout. One method to do this is by ‘boxing’ – mix half of bucket one and half of bucket two in a separate bucket.

Keep in mind that the final colour of the stain or clear finish can vary based on the quality of application, type of timber, natural colour, texture, grain, and porosity.


How To Apply Dryden OilStain

Dryden OilStain is one of NZ’s most popular Kwila maintenance products because it is so easy to use.

  • Apply with a wide bristle brush or a speed pad: For dressed or band-sawn Kwila, use a wide bristle brush or a speed pad – just avoid the lambswool types! A medium-nap roller or airless spray system can also be used to apply the oil to your decking.
  • Keep stirring the oil: Remember to regularly stir the oil throughout the application process to maintain a consistent colour. You don’t need to apply fresh oil to every part of the deck unless it needs it. But if you do start on any face, finish it off! This ensures a nice colour consistency across the Kwila deck.
  • Don’t thin or dilute: Dryden OilStain should not be thinned or altered in any way – you simply apply it to the wood surface and wipe off any excess solution. After the initial 30-60 minute waiting period, allow the deck to dry before applying another coat – it’s as easy as that!

Common Questions About Kwila Deck Maintenance

Does Kwila Wood Need Re-Coating Or Ongoing Maintenance?

Yes, although naturally rich in tannins and protective oils, Kwila decking requires regular re-coating to stay strong. Get started on your Kwila deck maintenance journey with a coating of:

Follow up with an annual wash and visual inspection.

Apply a fresh coat of wood oil or stain, depending on the condition of the timber – generally no sooner than 2 summers.

Apply a fresh coat of Dryden OilStain or a combo of OilStain and Colourtone+, depending on the condition of the timber – generally no sooner than 2 summers.

How Often Do I Need To Apply An Oil Or Stain To Kwila?

Because Kwila decking is exposed to the elements, it’s recommended that you give it an annual wash with clean water using a garden hose or soft brush (such as a car washing brush). A mild detergent solution can be used to remove stubborn contaminants. If it’s in need of recoating, clean and prep using Dryden LiquidTimberClean.

Recoat with Dryden OilStain or 1-2 coats of OilStain and Colourtone+ combined every few years – but this depends on the product used and the condition of the Kwila deck.

The timing and number of coats depend on the timber’s natural variations and the weather in your area. Generally, more direct sun means more frequent maintenance is needed.

Regular checks and appropriate maintenance coats will not only maintain its weather-resistant properties but also keep it looking impeccable.

How Often Does New Kwila Decking Need Oiling?

Give your brand-new Kwila deck two coats of Dryden OilStain to provide protection. After that, an annual wash and inspection are perfect, with standard maintenance carried out every 12-36 months. Doing so will maximise the oil’s protective qualities.

Follow this Kwila deck maintenance regimen and you can ultimately extend the lifespan of your investment.

Can You Stop Kwila From Going Grey?

Silvering or going grey is the natural process of Kwila and other timber species. Some like the silvered look, while others want to maintain or change the colour of their timber.

To stop your Kwila from going grey, it’s important to coat the timber with a high-quality coating. A premium solution like Dryden OilStain protects from the inside out and contains an anti-fungal additive to help protect against mould and it’s perfect with Colourtone+, which slows the Kwila from turning grey with its UV-blocking properties.