Gum, Shining

Shining gum is a native Australian hardwood gaining popularity for its versatility, interesting colour and speckled appearance.

Other Names

Ribbon Gum

Botanical Name

Eucalyptus nitens

Common Form
Sawn
Species Type
Hardwood
  • Overview

    • The native hardwood, shining gum, produces timber used predominantly in construction and furniture making. As a plantation managed timber subject to advanced silvicultural and milling methods, shining gum is gaining in popularity.

    Shining gum is prevalent in the mountain areas of east Gippsland and south-eastern NSW as well as the northern tablelands of NSW to an altitude of 1600m. It is a popular plantation timber as it can be extremely quick growing. Eucalyptus nitens is grown as a commercial plantation species in cool temperate regions around the world, including Tasmania, New Zealand, South Africa and Chile.

    Shining gum trees can reach heights of 70m, and diameters of 1-2m at chest height. Its form is desirable, with a straight bole up to two-thirds the height of the tree. Its smooth white or greyish bark is shed in long ribbons. It gets its name nitens (meaning shining) from the distinct glossy fruits, which have a varnished appearance, as well as the leaves, buds and bark, which can also appear to shine. The juvenile leaves have a pleasant fruity smell.

    Shining gum timber exhibits some interesting colours making it an appealing product for furniture making. The wood is pale pink and straight grained. It is suitable for general building, flooring, joinery, paneling, furniture and framing. It is also considered a good quality pulping species, although not as high yielding as some due to its lower density.

    Shining gum is not particularly durable (class 4) and is not recommended for external use, especially not in-ground. It is vulnerable to termites and the sapwood is susceptible to Lyctid borer.

    Shrinkage

    Very Low Low Medium High Very High
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    Tangential : Provides a simplified rating for tangential shrinkage. This is the measure of the percentage reduction in dimension from the unseasoned to 12% moisture content condition.
    9.40%

    Radial : Radial shrinkage is perpendicular to the growth rings. It is shrinkage in the direction towards the centre of the tree. Measurement is % value
    4.90%

    Unit Movement Tangential: This is the percentage of dimensional change for each 1% moisture content change between about 3% moisture content and the fibre saturation point for the particular species.
    0.33%

    Unit Movement Radial: This is the percentage of dimensional change for each 1% moisture content change between about 3% moisture content and the fibre saturation point for the particular species.
    0.22%

    Strength Group Strength groups are given for unseasoned (S1-S7) and seasoned (SD1-SD8) timber in accordance with AS 2878. S1 and SD1 yield the highest strength and stiffness whereas S7 and SD8 yield the lowest.

    Very High

    High

    Reasonably High

    Medium High

    Medium

    Reasonably Low

    Low

    Very Low

    Unseasoned:

    S1

    S2

    S3

    S4

    S5

    S6

    S7

    S8
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    Seasoned:

    SD1

    SD2

    SD3

    SD4

    SD5

    SD6

    SD7

    SD8
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    Stress Grade A stress grade is defined in AS 1720 as the classification of timber for structural purposes by means of either visual or machine grading. The stress grade indicates the basic working stresses and stiffnesses to be used for structural design purposes. Measured in MPa.

    Structural
    No. 1    		 Structural
    No. 2    		 Structural
    No. 3    		 Structural
    No. 4    		 Structural
    No. 5

    Unseasoned:

    F14

    F11

    F8

    F7

    F5

    Seasoned:

    F22

    F17

    F14

    F11

    F8

    Density per Standard Seasoned density is based on moisture content of 12%. Unseasoned density is an approximation as it depends on the moisture content at the time of measurement. Measured kg/m3.

    Seasoned:

    680kg/m3

    Unseasoned:

    1120kg/m3

    Joint Group The joint group is a classification of the strength of a species in joint design. The values are from 1 (very high strength) to 6 (very low strength).

    Very High

    High

    Reasonably High

    Medium

    Low

    Very Low

    Unseasoned:

    J1

    J2

    J3

    J4

    J5

    J6
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    Seasoned:

    JD1

    JD2

    JD3

    JD4

    JD5

    JD6
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    Colour The colour of seasoned heartwood can vary between species and often within a species. The information provided should be used as a general guide only. In most cases, the colour of sapwood is either a lighter shade of the heartwood or a white/cream colour.

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

    Modulus of Rupture - Unseasoned: This property is a measure of maximum stress which timber can momentarily sustain when loaded slowly and continuously as a beam. Measured in MPa.
    62

    Modulus of Rupture - Seasoned: This property is a measure of maximum stress which timber can momentarily sustain when loaded slowly and continuously as a beam. Measured in MPa.
    99

    Modulus of Elasticity - Unseasoned: This property is of importance in determining the deflection of a beam under load — the greater the stiffness, the less the deflection. Measured in GPa.
    10

    Modulus of Elasticity - Seasoned: This property is of importance in determining the deflection of a beam under load — the greater the stiffness, the less the deflection. Measured in GPa.
    13

    Maximum Crushing Strength - Unseasoned:

    Also referred to as compression strength. This property measures the ability of the timber to withstand loads applied on the end grain. Measured in MPa.
    31

    Maximum Crushing Strength - Seasoned: Also referred to as compression strength. This property measures the ability of the timber to withstand loads applied on the end grain. Measured in MPa.
    58

    Impact - Unseasoned: Provides the Izod value, which is the energy taken in joules (J) to fracture the timber.
    15

    Impact - Seasoned: Provides the Izod value, which is the energy taken in joules (J) to fracture the timber.
    16

    Toughness - Unseasoned: This is a measure of timber’s ability to resist shocks and blows, and is synonymous with impact strength. It is measured in Nm.
    Medium - 15 - 24 Nm

    Toughness - Seasoned: This is a measure of timber’s ability to resist shocks and blows, and is synonymous with impact strength. It is measured in Nm.
    Medium - 15 - 24 Nm

    Hardness - Unseasoned: Refers to the Janka hardness test and is a measure of timber’s resistance to indentation.
    4.8

    Hardness - Seasoned: Refers to the Janka hardness test and is a measure of timber’s resistance to indentation.
    5.8

    Durability

    Low Moderate Reasonably High High
    (0 - 5 yrs) (5 - 15 yrs) (15 - 25 yrs) (more than 25 yrs)

    In-Ground: Durability is defined as the inherent resistance of a timber species to decay, or to insect or marine borer attack. All references to durability refer to the heartwood only. A scale of low to high (durability class 4 = low; 1 = high) has been adapted for above and in-ground durability.

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    (0 - 7 yrs) (7 - 15 yrs) (15 - 40 yrs) (More than 40 yrs)

    Above ground: Durability is defined as the inherent resistance of a timber species to decay, or to insect or marine borer attack. All references to durability refer to the heartwood only. A scale of low to high (durability class 4 = low; 1 = high) has been adapted for above and in-ground durability.

    		 Check mark
    (0 - 20 yrs, usually < 5) (21 - 40 yrs) (41 - 64 yrs) (More than 60 yrs)

    Marine Borer Resistance: Indicates whether a species is resistant (R) or not resistant (NR) to marine borer attack.

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    Lyctid Borer Susceptibility: Indicates whether a species is susceptible (S) or not susceptible (NS) to lyctid borer attack.

    Susceptible

    Lyctid Borer Susceptibility - Other:

    Termite Resistance: Indicates whether a species is resistant (R) or not resistant (NR) to termites.

    Not Resistant

    Fire Properties

    0 1 2 3 4 5 6 7 8 9 10

    EFH Spread-of-Flame Index: This is a material's propensity to burn rapidly and spread flames based on a scale of 0 to 10 where 0 means that the materials will not cause flames to reach the ceiling and 10 indicates that the material could be expected to cause flames to reach the ceiling of a room within 10 seconds of ignition.

    EFH Smoke-Developed Index:This is a measure of the concentration (measured by optical density) of smoke a material emits as it burns. It is based on an arbitrary scale of 0 to 10. The higher the index, the greater the hazard from smoke is likely to be.

    Critical Radiance Flux - Lower: This measures the radiant (heat) energy required to sustain burning. It is used in Australia to regulate floor coverings. The requirements are set out in BCA Specification C1.10a, providing CRF values for floor coverings based on Class of building, the location within the building (general use or use in fire isolated exits) and whether or not the building is sprinkler protected or not. CRF is measured in kW/m2.

    >2.2 and <4.5

    Critical Radiance Flux - Higher: This measures the radiant (heat) energy required to sustain burning. It is used in Australia to regulate floor coverings. The requirements are set out in BCA Specification C1.10a, providing CRF values for floor coverings based on Class of building, the location within the building (general use or use in fire isolated exits) and whether or not the building is sprinkler protected or not. CRF is measured in kW/m2.

    >2.2 and <4.5

    Smoke Development Rate: This is the speed at which smoke increases as determined by testing flooring materials in accordance with AS ISO 9239.1. The rate is expressed in terms of percent/minutes. For buildings not protected with a sprinkler system, a maximum smoke development rate of 750 percent/minute applies.
    <750
    1 - non-combustible 2 - reasonably non-combustible 3 - slightly combustible 4 - combustible

    Fire Properties Group
    Number:

    Average Specific Extinction Area: This value is determined by the volume of smoke measured over the mass loss of the tested sample per test carried out in accordance with ‘Cone Calorimeter Test’ AS/NZS 3837. It is measured in units of m2/kg.
    <250

    Bushfire Resistance: Naturally bushfire-resisting timbers are those with inherent bushfire-resisting properties. Some species have been tested and a number are in the process of being tested and are measured by Bushfire Attack level (BAL). BAL -12.5: Ember attack, BAL – 19: Increasing levels of ember attack and burning debris ignited by windborne embers together with increasing heat flux between 12.5 and 19 kWm3, BAL – 29: Increasing levels of ember attack and burning debris ignited by windborne embers together with increasing heat flux between 19 and 29 kWm3.
    BAL 12.5 and 19 – Door and window joinery only
    Appearance

    The timber of shining gum, as its name implies, has lustrous qualities. The heartwood is a straw colour bursting with pink and yellow tints. The sapwood is not always easy to distinguish from the heartwood. The texture of shining gum timber is moderately coarse with a straight grain.

    Shining gum is not self-pruning. Branch retention creates a high incidence of features in milled timber for that reason. Pin-hole borer holes and the associated black stains of 'pencil streak' are often present, giving timber a speckled appearance. Growth rings are also a prominent feature of this timber.

    Common Applications

    Timber from shining gum has a wide range of uses, from pulp to sawn products. It is a good quality pulping species, although the wood is of slightly lower density than Tasmanian blue gum and therefore gives lower pulp yields. When plantation grown, it has the potential to produce sawlogs of select grade material if pruned. The timber is used for general construction: joinery, framing and flooring. The pale wood of young trees means the timber can be interchanged with mountain ash. It is also beginning to be used for furniture, where its discolouration is seen as a feature.

    Workability

    The general workability of shining gum timber is good, as it is not an extremely dense or hard timber. The green density of the timber is 1050 kg/m3 and air-dry density at 12% moisture is about 700 kg/m3.

    Shining gum is difficult to dry with moderate shrinkage and a high cell collapse necessitating reconditioning. It is prone to surface checking and requires careful drying and storage because of collapse.

    The wood is not as hard as blue gum, being moderately hard at 5.8 kN when dry. The heartwood of shining gum is not sufficiently durable for external use (class 4).

     

    Origin of timber
    NSW
    Readily Available
    NSW
    Shining gum timber is commercially available in NSW and Victoria.
    Source of timber
    Native Forest
    a kitchen with wooden cabinets and a countertop

    Joinery

    Timber joinery offers a classic, stylish touch to any interior or exterior space.
    a room with benches and paintings on the wall

    Flooring

    The warmth, strength and natural beauty of timber flooring is enduringly popular in a wide variety of domestic, commercial and industrial applications.

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