Hoop pine

Scientific name

Araucaria cunninghamii. Family: Araucariaceae

Local names

Queensland pine, colonial pine

Description and natural occurrence

A large tree attaining 50 m in height and 1.8 stem diameter. It usually has a straight cylindrical trunk. The bark in mature trees is rough and dark brown to nearly black in colour, while in young trees it is smooth with a tendency to peel off around the stem circumference. The hoops are apparent when bark is stripped from the trunk.

Occurs naturally in drier rainforests from Hastings River, New South Wales, to Far North Queensland and as far inland as 300 km in some places. It is also grown in plantations, mainly in southern Queensland. Outside Australia it extends to Papua New Guinea.

Sawn timber of this species is readily available, mainly from plantation grown trees.

Wood appearance

Colour. The heartwood ranges from pale cream to light yellow-brown with little difference between heartwood and sapwood.

Grain. Very fine and even textured. Growth rings usually visible but indistinct.

Wood properties

Density. 560 kg/m3 at 12% moisture content; approximately 1.7 m3 of seasoned sawn timber per tonne.

Strength groups. S6 unseasoned; SD5 seasoned.

Stress grades. F4, F5, F7, F8 (unseasoned), F7, F8, F11, F14, F17 (seasoned), when visually stress graded in accordance with AS 2858-2001, Timber - softwood - visually graded for structural purposes.

Joint groups. J4 unseasoned; JD4 seasoned.

Shrinkage to 12% MC. 3.8% (tangential); 2.5% (radial).

Unit shrinkage. 0.23% (tangential); 0.18 5% (radial). These values apply to timber reconditioned after seasoning.

Durability above-ground. Class 4 - life expectancy less than 7 years.

Durability in-ground. Class 4 - life expectancy less than 5 years.

Lyctine susceptibility. Not susceptible.

Termite resistance. Not resistant.

Preservation. Immature plantation grown stems are almost entirely sapwood, which typically comprises more than 50% of the stem radius even in mature plantations. Sapwood readily accepts commercial preservation impregnation but the heartwood cannot be adequately treated using currently available commercial processes.

Seasoning. To avoid distortion, framing sizes should be high temperature dried. Boards may be air dried or kiln dried at conventional or high temperatures.

Hardness. Soft (rated 5 on a 6 class scale) in relation to identation and ease of working with hand tools.

Machining. Machines and turns well to a smooth surface.

Fixing. No difficulty has been experienced with the use of standard fittings and fastenings.

Gluing. Can be satisfactorily bonded using standard procedures.

Finishing. Will readily accept stain, polish and paint.

Uses

Engineering. Preservative treated poles for pole frame construction, power poles.

Construction. General purpose softwood used as seasoned dressed timber in general house framing, flooring, lining, mouldings, laminated beams. Preservative impregnated for external or round form in fencing, pergolas, landscaping, retaining walls, playground equipment. Also used as structural plywood and particleboard.

Decorative. Furniture, plywood, joinery, turnery, carving.

Others. Boat building (masts, planking, deck beams, frames, marine plywood), aircraft construction, wood wool, paper products, arrow shafts, broom handles, cooperage, beehives, brushware, dowling, blind rollers, draughtman's implements, boat oars, musical instruments (violin and guitar bellies), scaffold planks, match splints.

Identification features

General characteristics

Sapwood. Indistinguishable from heartwood.

Heartwood. Pale cream to light yellow-brown.

Texture. Smooth, very uniform, grain straight except around knots.

Wood structure

Growth rings. Not prominent; transition from earlywood to latewood very gradual. False annual rings sometimes present as narrow and indistinct intermediate latewood bands.

Vessels. Absent.

Resin canals. Absent.

Parenchyma. Not visible with lens.

References

Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, 'Forest trees of Australia', 5th edn, CSIRO Publishing, Collingwood Australia.

Bootle, K 2005, 'Wood in Australia: types, properties and uses', 2nd edn McGraw-Hill, Sydney.

Hopewell, G (ed.) 2006, 'Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland, Class 1 and Class 10 buildings', books 1 and 2, Department of Primary Industries and Fisheries, Brisbane.

Ilic, J 1991, 'CSIRO atlas of hardwoods', Crawford House Press, Bathurst, Australia.

Standards Australia, 2000, 'AS 2082-2000: Timber - hardwood - visually stress-graded for structural purposes', Standards Australia.

Last updated 25 August 2010