Gum, Spotted | Corymbia maculata

Spotted gum is a premium Australian hardwood that is used widely in structural, exterior and internal applications.

Other Names: Lemon-scented Gum, Spotted Irongum, Eucalyptus maculata, Corymbia citriodora, Eucalyptus citriodora, Corymbia henryi, Eucalyptus henryi


Spotted gum is one of Australia’s premium native hardwoods with a striking appearance and a high degree of natural durability and strength, making it an ideal timber for a variety of structural, exterior and interior applications. Architects and designers throughout the world value spotted gum timbers for their back-sawn grain structure, attractive markings and vibrant colour palette.

Spotted gum is the common name for four species that grow along the east coast of Australia, from northeast Victoria to the northern tablelands of Queensland, with some occurrence in western areas of southern Queensland. Sawn timber from these species is generally available throughout Australia. These species have straight, slender trunks with smooth bark that is shed in patches, giving the trees their characteristic spotted appearance.


The species referred to as spotted gum vary in appearance but not in durability class or other properties. The heartwood ranges from light brown through to dark red-brown hues. Sapwood is usually white to light brown in colour. The presence of a wavy grain can produce an attractive fiddle-back figure. The wood has a slightly greasy feel, a characteristic that aids machining and boring. Spotted Gum components that are 18mm thick or greater do not require fire retardant treatment for use in construction in bush-fire prone areas.

Spotted gum is used in engineering applications such as wharf and bridge construction, railway sleepers, cross-arms and mining timbers. It is suitable for a range of building applications, such as posts and poles, framing, flooring, lining, decking and cladding. Spotted gum is also used in the manufacture of veneer and plywood. Other applications include boatbuilding, tool and implement handles, polo sticks and diving boards. Compared to other Australian hardwoods, spotted gum is a minimal staining timber as it is less prone to bleed-through of tannins than other species. Spotted gum is also a good timber for carving and woodturning.






Very Low Low Medium High Very High
Radial: 3 - 4
Unit Movement: 0.38 %

Strength Group

Very High High Reasonably High Medium High Medium Reasonably Low Low Very Low

Stress Grade

No. 1
No. 2
No. 3
No. 4
No. 5
Unseasoned: F27 F17 F14 F11 F8
Seasoned: F34 F27 F22 F17 F14

Density per Standard

Unseasoned: 1150 kg/m3
Seasoned: 1100 kg/m3

Joint Group

Very High High Reasonably High Medium Low Very Low


  White, yellow, pale straw to light brown Pink to pink brown Light to dark red Brown, chocolate, mottled or streaky

Mechanical Properties

Modulus of Rupture - Unseasoned: 99
Modulus of Rupture - Seasoned: 150
Modulus of Elasticity - Unseasoned: 18
Modulus of Elasticity - Seasoned: 23
Maximum Crushing Strength - Unseasoned: 50
Maximum Crushing Strength - Seasoned: 75
Impact - Unseasoned: 20
Impact - Seasoned: 24
Toughness - Unseasoned: High - 25 Nm and above
Toughness - Seasoned: High - 25 Nm and above
Hardness - Unseasoned: 8.0
Hardness - Seasoned: 11


Low Moderate Reasonably High High
(0 - 5 yrs) (5 - 15 yrs) (15 - 25 yrs) (more than 25 yrs)
(0 - 7 yrs) (7 - 15 yrs) (15 - 40 yrs) (More than 40 yrs)
Above ground:
(0 - 20 yrs, usually < 5) (21 - 40 yrs) (41 - 64 yrs) (More than 60 yrs)
Marine Borer Resistance:
Lyctid Borer Susceptibility: Susceptible
Termite Resistance: Resistant

Fire Properties

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
EFH Ignitibility:
0 1 2 3 4 5 6 7 8 9 10
EFH Spread-of-Flame Index:
EFH Smoke-Developed Index:
Critical Radiance Flux - Lower: >2.2 and <4.5 kW/m2
Critical Radiance Flux - Higher: ≥4.5 kW/m2
Smoke Development Rate: <750
1 - non-combustible 2 - reasonably non-combustible 3 - slightly combustible 4 - combustible
Fire Properties Group
Group Number - Other: For plywood-

  • Fire Properties - EFH Spread-of-flame Index: 7
Average Specific Extinction Area: <250
Bushfire Resistance: BAL 12.5, 19 and 29 – All AS3959 required applications


Botanical Name: Corymbia maculata
Preferred Common Name: Gum, Spotted
Other Names: Lemon-scented Gum, Spotted Irongum, Eucalyptus maculata, Corymbia citriodora, Eucalyptus citriodora, Corymbia henryi, Eucalyptus henryi
Species Type: Hardwood


Spotted gum timbers are available in a range of colours depending on the location of the source forest. The heartwood ranges from light brown through definite browns to deep red-brown hues. Sapwood is white to light brown in colour and can be up to 50mm wide. Spotted gum is a moderately coarse and uneven textured wood with some timbers having the additional feature of a wavy grain, giving rise to an attractive fiddleback figure.


Common Applications

Spotted gum has a long history of use in engineering applications such as wharf and bridge construction, railway sleepers, cross-arms and mining timbers. It is used for a variety of applications, including structural building members, such as posts and poles, and for framing, flooring, lining, decking and cladding. It is also used in boatbuilding and is the primary Australian timber used for the handles of tools and implements that are subject to high impact forces. Spotted gum is a suitable carving and woodturning timber and is used in the manufacture of both indoor and outdoor furniture. Outdoor furniture in spotted gum has consistently won industry awards in Australia and is exported to destinations around the world.


Common Form

Sawn, Veneer


Spotted gum machines well due to its natural greasiness and there is no difficulty using the timber with standard fittings and fastenings. As with most high-density species, machining and surface preparation should be done immediately before gluing. Spotted gum readily accepts paint, stains and polish. It has a lower tannin content than most other eucalypts, therefore staining of paintwork or brickwork as a result of water running over unpainted timber surfaces is less likely to occur.


Origin of Timber

NSW, VIC, QLD, Oceania

Readily Available

NSW, VIC, QLD, Oceania

Availability - Further Information

Sawn timber from these species is generally available throughout Australia, and spotted gum is currently the highest volume native hardwood harvested in Queensland. Spotted gum is exported to the US and a range of other destinations.

Source of Timber

Native Forest, Plantation


  • Decking

    Timber decking creates spaces that are functional, practical and aesthetically pleasing. With the right design and care a timber deck will make a valuable addition to any home or business, creating an outdoor living space that will be enjoyed for years to come.

  • Exterior Rails and Balustrades

    This guide provides general information on member sizes, connections and suitable materials for construction of handrails and balustrades in external applications. Commonly built from treated softwood and durable hardwoods, they can be finished with a wide variety of paints or stains, creating balustrades that with the right care and attention, will comfortably withstand the elements for decades to come.

  • Exterior Stairs

    For outdoor applications, timber is one of the leading material choices. Timber use in external staircase applications creates structures of strength and durability, sheathed in a natural beauty that blends seamlessly with the outdoor environment.

  • External Cladding

    The natural appeal, versatility and strength of timber makes it the superior choice for external cladding. Through specification, planning, design and finishing processes, timber cladding not only creates a building of superior strength, acoustic and thermal performance but also creates a place of beauty, style and natural appeal.

  • Flooring

    Whether for structural or finished flooring applications, timber offers durability, versatility and adaptability. The warmth, strength and natural beauty of timber flooring has proved enduringly popular in a wide variety of interior settings.

  • Interior Stairs

    Timber should be the material of choice for designers seeking internal staircases of strength, beauty and durability. The construction procedure described here applies to most general type stairs of either conventional or contemporary construction.

  • Pergolas

    A timber pergola is a practical, functional and attractive way to extend living and entertainment spaces into the outdoors.

  • Retaining Walls (Landscaping)

    When it comes to retaining wall, landscape design and construction, timber is the natural choice. A material that is durable, sturdy and reliable, it boasts natural aesthetics that help it blend seamlessly with the outdoors. Careful consideration during the specification and design process will facilitate the creation of a long lasting, durable and eye catching timber retaining wall that will complement its surrounding landscape for years to come.

  • Structural Timber Poles

    Timber poles are utilised in structural construction to provide support for gravity loads and resistance against lateral forces. Not only serving a structural function, timber poles provide many aesthetic benefits, with their use in construction often complementing architectural designs aimed at harmonisation with the natural environment.

  • Timber Mouldings

    Mouldings are extremely versatile and durable, enhancing the aesthetics of any interior and functioning as the icing on the cake for designs with a focus on beauty and splendour.

  • Timber Portal Frames

    For buildings that require large spans and column free interiors, timber portal frames provide one of the most aesthetically pleasing solutions. Utilising modern engineering technology, portal frame design transforms timber into a highly effective, efficient and economical structural product. This application guide provides a comprehensive overview of the process of using timber in the specification, fabrication and erection of portal frame structures.

Case Studies

  • ARkit Prefab and Prefabricated Eco Homes

    Prefab and Prefabricated Eco Homes Australia: ARkit’s timber kit homes change the way we think about sustainable building and living.

    Applications: Decking, External Cladding, Flooring, Framing, Internal Paneling, Windows,

  • Eastern Precinct, University of Melbourne, Parkville

    The durability and warmth of timber supports the University of Melbourne’s model, providing a new learning landscape at the Eastern Precinct Student Centre.

    Applications: Decking, Doors, External Cladding, Flooring, Internal Paneling, Windows,

  • Kew House 3

    Vibe Design Group’s, Kew House 3 uses timbers natural warmth and appeal to not only wrap a dynamic exterior but also evoke a journey of discovery within the home.

    Applications: Decking, External Cladding, Fencing, Flooring, Timber Joinery Products,

  • Letterbox House, Blairgowrie

    A holiday home that uses a range of commercial timber products and salvaged on-site timber to award winning effect.

    Applications: Architectural Roof Trusses, Doors, External Cladding, Fencing, Flooring, Framing, Windows,

  • Mingara One Fitness Centre

    A breathtaking addition to the Mingara Recreation Club campus on the NSW central coast, covering 2000sqm of commercial gymnasium over two levels.

    Applications: Doors, External Cladding, Flooring, Interior Stairs, Internal Paneling,

  • National Portrait Gallery, Canberra

    Jarrah, Spotted Gum, Blackbutt and Victorian Ash play an essential role in the National Portrait Gallery’s expression of Australian identity.

    Applications: Architectural Roof Trusses, External Cladding, Flooring, Framing, Interior Stairs, Internal Paneling, Windows,

  • Svarmisk Resort Centre, Mt Beauty

    A striking eco-resort that embodies the essence of new and recycled timber working together to form a unique, innovative and sustainable development.

    Applications: External Cladding, Flooring, Framing, Interior Rails and Balustrades, Interior Stairs, Internal Paneling, Pergolas, Shear walls, Structural Timber Poles,

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