A Handsome Western Australian Red Hardwood
Karri (Eucalyptus diversicolor) grows in the high-rainfall forests of south-west Western Australia and is one of the tallest hardwoods in the world. Its heartwood is a warm reddish-brown — paler than Jarrah when fresh, maturing to a more uniform brown with pink and red overtones — with a clearly distinguishable creamy sapwood. The grain is typically interlocked, sometimes wavy, with an even, moderately coarse texture, and natural features such as gum veins and insect trails add to its character. Karri is strong and durable. With a Janka hardness around 9 kN and a density near 900 kg/m³, it is rated Durability Class 2 above ground (Class 3 in ground) and, helpfully for cladding, its heartwood is not susceptible to lyctid borer. Karri is recognised for bushfire applications at BAL-12.5 and BAL-19, and can be used up to BAL-29 in conjunction with non-combustible wall cladding and an enclosed subfloor (confirm per AS 3959). As with Jarrah, WA supply has tightened and Karri is now drawn largely from regrowth forests, so availability should be confirmed early.
Why Choose Karri Cladding
Technical Specifications
Botanical name
Eucalyptus diversicolor
Heartwood colour
Reddish-brown (paler than Jarrah), maturing to uniform brown with red/pink overtones
Natural durability
Class 2 above ground; Class 3 in ground
Janka hardness
approx. 9 kN
Density (seasoned)
approx. 900 kg/m³
Termite/borer
Durable heartwood; not lyctid-susceptible
Bushfire rating
BAL-12.5 & BAL-19; up to BAL-29 with non-combustible cladding & enclosed subfloor (confirm per AS 3959)
Grain & texture
Interlocked, sometimes wavy grain; even, moderately coarse texture
Typical applications
External cladding, flooring, joinery, furniture, structural
Where Karri Cladding Performs Best
External wall cladding for homes wanting warm red-brown tones.
Feature facades and architectural projects valuing Karri’s interlocked grain.
Bushfire-area cladding at BAL-12.5/19, or BAL-29 with appropriate construction (confirm per AS 3959).
Projects seeking a WA red hardwood alternative to Jarrah.
Internal feature walls and lining.
Mixed-material schemes combining Karri with render, stone, metal or glass.
Karri Cladding Profiles & Grades
Karri cladding can be supplied in a choice of popular profiles to suit the look you are after — from crisp shiplap and tongue-and-groove boards that create clean, contemporary shadowlines, through splayed weatherboard and board-on-board profiles for a more traditional feel, to square-edge and channel profiles for a modern, linear aesthetic. Cover width has a big impact on the finished look: narrower boards read as fine and detailed, while wider boards give a bolder, more streamlined facade. Our team can talk through the options and help you choose the profile and width that best suit your design and budget. Grade is the other key choice. Cleaner, lower-feature grades give a calm, uniform appearance, while character or feature grades showcase the natural colour variation, grain and markings that make Karri distinctive. Because timber is a natural product, every board is unique, so we recommend reviewing a current sample or batch before committing to a large order. Tell us the profile, width and grade you are leaning towards and we will confirm what is available and provide samples where possible.
Get Your Free QuoteWorking With and Maintaining Karri
Karri is dense and has an interlocked grain that can be challenging to machine, so use sharp tooling, pre-drill near board ends and fix with quality fixings (stainless steel near the coast). Fix cladding over battens with a drained, ventilated cavity, detail to shed water and seal cut ends. Where a bushfire rating applies, follow AS 3959 requirements for the relevant BAL and construction detail. Karri can move in service and is best installed well seasoned; maintain consistent detailing and ventilation. To preserve its red-brown colour, finish with a quality UV-stabilised exterior coating or oil and re-apply periodically; left uncoated it will weather to silver-grey while retaining durability. Reseal cut ends and maintain the coating to maximise service life.
Get Your Free QuoteSustainable & Ethically Sourced
JVS Timber sources Karri from certified WA producers, now drawn largely from regrowth forests under strict sustainability management, and supplies product compliant with Australian industry standards. Choosing a durable hardwood that lasts for decades is itself a sustainable decision. As WA supply has tightened, we recommend confirming Karri availability early. FSC-certified options may be available on request.
Get Your Free QuoteKarri Sizes & Availability
JVS Timber supplies Karri cladding in a choice of profiles and grades, in a range of widths and lengths. As WA hardwood supply has tightened, we recommend confirming availability early so we can reserve and schedule delivery to your site Australia-wide. Tell us your profiles, sizes and quantities and we will confirm current stock and competitive trade pricing.
Get Your Free QuoteKarri Cladding — Frequently Asked Questions
Karri and Jarrah both come from south-west WA and share rich red tones, but Karri is generally a little lighter, more uniform and straighter-grained when fresh, and matures to a more even brown. Jarrah tends to deeper burgundy tones. Karri’s heartwood is also not lyctid-susceptible.