Gum, Shining | Eucalyptus nitens

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

Other Names: Ribbon Gum

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.

Properties

Shrinkage

Very Low Low Medium High Very High
Tangential:          
9.4
Radial: > 5
Unit Movement: 0.33 %

Strength Group

Very High High Reasonably High Medium High Medium Reasonably Low Low Very Low
Unseasoned:S1S2S3S4S5S6S7
Seasoned:SD1SD2SD3SD4SD5SD6SD7SD8

Stress Grade

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

Unseasoned: 1050 kg/m3
Seasoned: 700 kg/m3

Joint Group

Very High High Reasonably High Medium Low Very Low
Unseasoned:J1J2J3J4J5J6
Seasoned:JD1JD2JD3JD4JD5JD6

Colour

  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: 62
Modulus of Rupture - Seasoned: 99
Modulus of Elasticity - Unseasoned: 10
Modulus of Elasticity - Seasoned: 13
Maximum Crushing Strength - Unseasoned: 31
Maximum Crushing Strength - Seasoned: 58
Impact - Unseasoned: 15
Impact - Seasoned: 16
Toughness - Unseasoned: Medium - 15 - 25 Nm
Toughness - Seasoned: Medium - 15 - 25 Nm
Hardness - Unseasoned: 4.8
Hardness - Seasoned: 5.8

Durability

Low Moderate Reasonably High High
(0 - 5 yrs) (5 - 15 yrs) (15 - 25 yrs) (more than 25 yrs)
In-Ground:
(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: Not 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: >2.2 and <4.5 kW/m2
Smoke Development Rate: <750
1 - non-combustible 2 - reasonably non-combustible 3 - slightly combustible 4 - combustible
Fire Properties Group
Number:
Average Specific Extinction Area: <250
Bushfire Resistance: BAL 12.5 and 19 – Door and window joinery only

Description

Botanical Name: Eucalyptus nitens
Preferred Common Name: Gum, Shining
Other Names: Ribbon Gum
Species Type: Hardwood

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.

Common Form

Sawn

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, VIC, NZ

Readily Available

NSW, VIC

Availability - Further Information

Shining gum timber is commercially available in NSW and Victoria.

Source of Timber

Native Forest, Plantation

Applications

  • 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.

  • Framing

    Since people began building simple shelters, wooden framing has played an important role in shaping structures of many kinds. One of the most popular types of wooden framing is known as lightweight timber construction.

  • Internal Paneling

    Timber paneling creates interiors as warm as they are stylish. Commonly using an MDF or plywood substrate, internal timber paneling is natural and versatile and comes as either solid natural timber panels or as sheets of engineered wood products

  • Timber Joinery Products

    Timber joinery products offer a classic, unique and stylish touch to any interior design.

  • 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

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