Grey Gum

Grey Gum
Botanical name
Eucalyptus propinqua
calyptus punctata
Origin
Grey Gum grows in the coastal districts from the Hawkesbury River in New South Wales to Maryborough in Queensland.
Trading names
Grey Gum
Appearance
Heartwoodred.
Sapwooddistinctively paler.
Texturemoderately coarse and even.
Grainusually interlocked.
Grub holesoften present.
General comment
Density and interlocking grain make it difficult to work when dry.
Common uses
Heavy engineering construction, marine construction, poles, piles, sleepers, flooring, decking.
Properties
(See notes below)
Hardness rating
Average Hardness Rating - Dry: Very Hard

Lyctid Susceptibility of Sapwood
Not susceptible
(source AS 5604)

Termite Resistance of Heartwood (inside above ground)
Resistant
(source AS 5604)

Marine Borer Resistance of Heartwood
Class 2
(source AS 5604)

Natural Durability Rating of Heartwood Above Ground
Class 1
(source AS 5604)

Natural Durability Rating of Heartwood In-Ground Contact
Class 1
(source AS 5604)
Notes

Density: 'Green Density' (GD) is the density of the wood at the time the living tree is felled. It varies considerably with the season, weather conditions, the age of the tree and so on; the quoted figure must therefore be accepted as a guideline only and when accurate green density figures are required for, say, assessment of transport costs, it is advisable to carry out accurate determinations on the materials involved.

'Dry Density' or 'Air Dry Density' (ADD) is the average density of the wood at 12 per cent moisture content. It too varies with conditions of growth, climate and maturity of wood.

There are published figures for both Green Density and Air Dry Density of most commercial species.

The figures given above have been rounded to the nearest 50.

Hardness rating: The hardness rating of a timber species is measured by the Janka Test. This is a standard test which measures the penetration into the timber of a common load and projectile. The results relate to a hardness capacity of the material and are expressed in kN. This information is useful where the timber may be subject to potential damage from impacts e.g. a dance floor. There are 2 sets of published figures; one for 'Green' or freshly felled timber and one for seasoned timber - i.e. timber with a moisture content of 12%.

The ratings given here are:
Soft - less than 5.5
Moderate - 5.5 to 7.0
Hard - 7.1 to 10.0
Very Hard - greater than 10.0.

Lyctid susceptible sapwood: Only the sapwood of some hardwoods is susceptible to lyctid borer attack. No softwoods are susceptible to attack.

Natural durability ratings: The natural durability rating of a timber species is a rating of the timber's resistance to attack by wood destroying fungi and wood destroying insects. The sapwood of all timber species has poor resistance and so the natural durability rating applies only to the heartwood of a timber species. The rating is based on the testing of stakes and poles embedded in the ground and on expert opinion of historical performance. There are 2 sets of ratings: one for above ground use and one for in-ground contact use. The lower the number the higher the performance in terms of durability. This information is useful for specifying material for external or exposed applications.

 

1
Grey Ironbark
Grey Box

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