Key Takeaways Four practical finish options: Clear Factory Coat – No UV Protection (natural silvering), UV Inhibitor that allows the woods natural grain to still shine through, tinted oil options like Smokey Grey, Obsidian Black, and Charred Ironbark (Shou Sugi Ban). Clear factory penetrative coated cladding is zero-maintenance and covered by warranty: Leaving Class 1 reclaimed or sustainably sourced hardwood to leave it to weather is all part of the 15 year warranty. Same NZBC detailing for every finish: All coating paths use standard NZBC-compliant profiles and AS1/E2 detailing, so you do not need to redesign to use Australian Hardwood cladding. Base your choice on site and maintenance: Let climate exposure (coastal, alpine, urban) and your client’s willingness to maintain the timber guide the decision alongside aesthetics. Choosing an exterior timber finish often feels like balancing what the client wants it to look like against how much maintenance they are willing to do. With Australian hardwood, that decision is much simpler than it looks. Because Class 1 hardwoods get their durability and weather resistance from their natural density and cellular make up, the finish choice comes down to aesthetics and upkeep rather than timber protection (although this is still important). When looking through hardwood cladding options, four main paths emerge: factory coating with clear oil (no UV inhibitor) which will allow natural silvering, UV Inhibitor that allows the woods natural grain to still shine through, tinted penetrating oil like Smokey Grey, Obsidian black (both with UV inhibitors), and charred Ironbark which also comes with a factory coating of Black Ash Tint. Here is how to match the right finish to your project brief across New Zealand climate zones. What Finish Options Are Available for Australian Hardwood Cladding? All three finishes can be applied in the factory across LMA’s exterior cladding range. Factory pre-finishing ensures full coverage on all sides, consistent drying, and fewer trades to coordinate on site. Importantly, all three options use identical NZBC-compliant profile dimensions, so you can change the finish selection late in concept stage without redesigning cavity details. 1. Factory Coat of Oil Only: The Zero-Maintenance Path Leaving hardwood cladding uncoated following its factory coat allows the timber to weather naturally, shifting from rich native tones into a silver-grey patina over time. Class 1 Australian hardwoods (like Spotted Gum, Ironbark, Blackbutt, and Tallowwood) are highly dense and durable – class 1 meaning 40 years plus natural durability. Uncoated timber goes through a transitional phase where sun and rain weather different elevations at varied rates. In typical NZ conditions, uniform silvering takes about 12 to 18 months. As you can imagine, not oiling your cladding is a little bit like us aging over time. Sunscreen helps to prevent sun spots, markings, wrinkles etc. The same can be said for hardwood cladding. You can let the timber age gracefully (minimum maintenance requirement to wash down your cladding every 12 months to free it from dirt, grime and potential mould build up if any) and over time it will surface check, have wrinkles on the service but still be fit for purpose. That being, ensuring that your house is watertight for a minimum of 15 years. LMA Timber’s product warranty covers not recoating cladding once installed, meaning leaving the timber natural will not void performance guarantees for 15 years. This makes it a smart choice for coastal baches, multi-residential projects, or commercial builds where ongoing painting budgets do not exist. 2. Pre-Oiled: Colour Retained, Low Maintenance If your client wants to keep the warm, rich honey and amber tones of freshly milled hardwood, applying a UV inhibitor like Cutek CD 50 Extreme – Colourtone Autumn is the right path. Factory pre-oiling applies deep-penetrating natural timber oils under controlled conditions before the cladding arrives on site. This coats all four sides (cut ends must be oiled onsite), protecting the timber from sudden moisture changes during construction. It also avoids common on-site issues like weather delays, lap marks, or uneven coating thickness. Keeping that rich timber colour requires maintenance. Depending on site exposure, orientation, and UV levels, a fresh coat of a UV inhibitor oil will be needed every 2 to 3 years. North and west facing walls usually need attention earlier than shaded south walls. Re-oiling is straightforward: wash the timber down with a tannin / oil remover and reapply a compatible oil. There is no need for sanding or stripping because the right quality penetrating oils like Cutek offer should not form a brittle film that peels or flakes. 3. Smokey Grey Tinted Oil: Controlled Silvering Smokey Grey Tinted oil gives you the look of silvered timber immediately while providing an even tone across the entire building from day one. Natural silvering happens gradually, which means north faces silver faster than shaded walls under eaves. Smokey Grey combines a penetrating protective oil with a subtle smokey grey pigment, delivering a uniform grey appearance to the boards before installation. As the pigment slowly wears away over 2 to 3 years, the timber underneath naturally silvering takes over smoothly. This option works well for commercial or high-end residential briefs where the client wants an immediate silvered look without waiting through the patchy intermediate phase of natural weathering. 4. Charred Ironbark (Shou Sugi Ban): Maximum Durability, Bold Aesthetic Charred Ironbark uses the traditional Japanese Shou Sugi Ban (Yakisugi) method, burning the timber surface to create a durable carbonised outer layer. While charred timber in New Zealand is usually made from softwoods like Cedar or modified Pine, LMA applies this process to Class 1 Ironbark. Combining an extremely dense hardwood substrate with a charred exterior creates a facade that naturally resists fire, UV damage, insects, and fungal decay. Visually, Charred Ironbark provides a deep, textured black finish. After charring, the timber is factory-sealed with Black Ash UV Tint to bind the carbon layer so it does not rub off during handling and installation. It offers a striking architectural option for harsh coastal or alpine sites where painted softwoods struggle to last. The biggest asset of Charring Iron Bark is the carbon layer that is formed. This layer absorbs and deflects sunlight, stopping ultraviolet radiation from breaking down the underlying wood. If you have ever been into a forest that has burnt down 5-6 years later you will still see that charring – it has hardly faded and it has protected the tree. It offers the ultimate performance and protection against weathering and UV damage. Summary of Finish Options Factory Clear Coated: Zero ongoing maintenance, silvering covered by warranty, great for low-maintenance briefs. UV Inhibitor Tint: Preserves warm natural hardwood colours, needs simple re-oiling every 3 to 5 years. Smokery Grey Tinted Oil: Delivers an immediate, even grey appearance on day one that ages naturally over time. Charred Ironbark: Heavy-duty Class 1 hardwood with a carbonised layer for a bold, lasting black finish with Black Ash Tint. Which Finish Is Right for Your Project? Three Questions to Ask To narrow down the right finish quickly during concept design, run through these three questions: What is the client’s appetite for maintenance? If they want zero maintenance costs and no upkeep schedule, specify clear factory coated. If they prefer the original timber colour and accept a wash and re-oil every 2 to 3 years, specify a UV Inhibitor like Cutek CD 50 Extreme Colourtone Autumn. If they want a bold black feature with minimal upkeep, go with Charred Ironbark. What is the site exposure zone? Severe coastal locations with salt spray and high UV suit Factory Coated or Smokey Grey tint options well. In sheltered urban zones, all four finishes perform reliably. What visual outcome does the design call for? Match the finish directly to the look you want: immediate grey (Smokey Grey Tinted Oil), long-term natural patina (Factory Coated), warm timber tones (UV Inhibitor Oil), or solid black (Charred Ironbark). Finish Decision Matrix Finish Option Maintenance Required Visual Outcome NZ Exposure Suitability Warranty Covered Factory Coat / Natural None – apart from wash down once every 12 months Natural silver-grey patina over 12–18 months All zones (Coastal, Alpine, Urban) Yes UV Inhibitor Re-oil every 2-3 years Warm natural timber tones retained All zones Yes Smokey Grey Tinted Oil Low (one transition cycle) Even grey on day one, ages into patina All zones Yes Charred Ironbark Very low – every 5-7 years – recoat with Black Ash Tint Deep carbonised black with rich texture All zones (Extreme Coastal & Alpine) Yes Does Australian Hardwood Cladding Need a Finish to Meet NZBC Requirements? Architects often ask about leaving the cladding uncoated and what this might mean for the building code / warranty. LMA hardwood cladding meets New Zealand Building Code (NZBC) clauses B1 Structure, B2 Durability, and E2 External Moisture regardless of the finish you choose. NZBC Clause B2 requires cladding materials to last at least 15 years. Class 1 Australian hardwoods naturally achieve an above-ground durability rating of over 40 years without needing chemical treatments or protective coatings. If reclaimed timber is being used for cladding purposes, hesitation around this usually stems from concerns about old bolt holes or split grain. The milling process involves recovering large hardwood timbers like telegraph poles and wharf beams, which are then demetalled, inspected, and precision-cut into new profiles. Any old bolt holes or split grain timbers to not make the strict grading rules that are in place to ensure it meets the requirements of the New Zealand Building Code. You can read more about how reclaimed timber is sourced and processed to see how old fixings and surface defects are removed entirely, leaving clean heartwood ready for standard cavity installation. For quick specification work, LMA profiles are listed on EBBOS and MasterSpec for easy access to CAD details and technical datasheets. How Does LMA Australian Hardwood Perform Across NZ Climates? New Zealand climate conditions vary widely, from salt winds in Northland to freeze-thaw cycles in the Southern Alps. Australian Hardwood has proven performance across all of these environments, which you can see showcased across various regions in recent architectural projects. In alpine areas like Castle Hill (600 metres above sea level with winter temperatures down to −8°C), rapid temperature changes can cause softer timbers to split around fixings. The high density and stability of Class 1 hardwood helps to resist thermal shock and moisture movement, keeping the building envelope tight. If choosing the reclaimed cladding option, this gives you a clear sustainability story for clients focused on environmental footprint. Reusing existing hardwood avoids the processing footprint of new timber. Independent testing shows reclaimed Australian hardwood locks in carbon stored decades ago, offering 2 to 3 times the embodied carbon benefits of newly harvested softwoods over its lifetime. Frequently Asked Questions Does Austraian hardwood cladding need to be oiled to stay durable? No. Class 1 Australian hardwoods have natural density and extractives that protect against rot, decay, and insects. Oiling following its factory coat application is purely an aesthetic choice to keep the warm timber colour. Leaving the timber uncoated will naturally let the timber weather over time but it will not void the warranty. How long does it take for hardwood cladding to turn silver in NZ? In typical NZ weather, uncoated hardwood starts changing colour within a few months and reaches a full silver-grey patina in about 12 to 36 months, depending on building orientation and rain exposure. What is the difference between Smokey Grey Tinted Oil and natural silvering? Smokey Grey gives you an immediate, uniform grey look from day one. Natural silvering happens gradually over 12 to 36 months as UV light and rain weather the raw wood face. Is Charred Ironbark cladding suitable for coastal areas? Yes. Ironbark is a Class 1 hardwood and Charred timber cladding is well-suited for coastal regions because the carbonization process removes sugars that attract pests and creates a natural, water-resistant barrier against harsh weather without breaking down. Does my choice of finish affect building consent? No. All four finish options use the same NZBC-compliant profiles meeting B1, B2, and E2 requirements. Code compliance comes from the Class 1 timber itself, so changing finishes does not require new detailing or consent changes. Can factory-applied finishes be ordered directly from LMA Timber? Yes. LMA supplies pre-oiled, UV Inhibitor and Smokey Grey Tint amongst many others, and charred finishes directly from the factory. Factory coating ensures consistent coverage on all sides and avoids weather delays on site. Specify Australian Hardwood Cladding with Confidence Selecting a finish for Australian hardwood cladding does not have to mean choosing between appearance and performance. Whether your project needs the simple zero-maintenance path of natural silvering, the warm tones of UV Inhibitor oil timber, or the strong presence of Charred Ironbark, LMA Australian hardwood offers a warranty-backed, NZBC-compliant option built for New Zealand conditions. If you have further technical questions, feel free to browse our frequently asked questions or get in touch directly to request timber samples for your office.
