GPEMS

Grey Gum

Botanical nameEucalyptus propinqua,Eucalyptus punctata
Origin
Grey Gum grows in the coastal districts from the Hawkesbury River in New South Wales to Maryborough in Queensland.
Trading namesGrey Gum
Appearance
Heartwood red
Sapwood distinctively paler.
Texture moderately coarse and even.
Grain usually interlocked.

Grub holes often present.
General comment
Density and interlocking grain make it difficult to work when dry.
Common usesHeavy engineering construction, marine construction, poles, piles, sleepers, flooring, decking.
Properties
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.