Hoop pine

Scientific name

Araucaria cunninghamii. Family: Araucariaceae

Other names

Queensland pine; colonial pine

Description

  • Large tree growing to 50m high and 1.8m stem diameter.
  • Usually has a straight cylindrical trunk.
  • Bark in mature trees is rough and dark brown to nearly black.
  • Bark in young trees is smooth and can peel off around the stem circumference.
  • Hoops are apparent when bark is stripped from the trunk.

Occurrence

  • Occurs naturally in drier rainforests from Hastings River, New South Wales to Far North Queensland and 300km inland in some places.
  • Grown in plantations, mainly in southern Queensland.
  • Occurs in Papua New Guinea.
  • Sawn timber is readily available, mainly from plantation trees.

Appearance

Colour

  • 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.

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.
  • Impregnated with preservatives for external or round form in fencing, pergolas, landscaping, retaining walls, playground equipment.
  • 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.

Properties

  • Density: 560kg/m3 at 12% moisture content; about 1.7m3 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 according to AS 2858—2008: 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 year).
  • Lyctine susceptibility: not susceptible.
  • Termite resistance: not resistant.
  • Preservation: immature plantation-grown stems are almost entirely sapwood, which typically consists of more than half the stem radius even in mature plantations. Sapwood readily impregnates with preservative but the heartwood can’t be adequately treated using available commercial processes.
  • Seasoning: to avoid distortion, framing sizes should be dried in high-temperatures; boards may be air-dried or kiln-dried at conventional or high temperatures.
  • Hardness: soft (rated 5 on a 6-class scale) to indent and work with hand tools.
  • Machining: machines and turns well to a smooth surface.
  • Fixing: no difficulty using standard fittings and fastenings.
  • Gluing: satisfactorily bonds using standard procedures.
  • Finishing: readily accepts stain, polish and paint.

Identification features

General characteristics

  • Sapwood: indistinct from heartwood.
  • Heartwood: pale cream to light yellow-brown.
  • Texture: smooth, very uniform, grain straight except around knots.

Wood structure

  • Growth rings: not prominent; very gradual transition from earlywood to latewood; false annual rings sometimes present as narrow and indistinct, intermediate, latewood bands.
  • Vessels: absent.
  • Resin canals: absent.
  • Parenchyma (soft tissue): not visible with lens.

Research and resources

  • Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, Forest trees of Australia, 5th ed., CSIRO Publishing, Collingwood, Australia.
  • Bootle, K 2005, Wood in Australia: Types, properties and uses, 2nd ed. McGraw-Hill, Sydney.
  • Ilic, J 1991, CSIRO atlas of hardwoods, Crawford House Press, Bathurst, Australia.
  • Queensland Government, DAF 2018, Construction timbers in Queensland: Properties and specifications for satisfactory performance of construction timbers in Queensland. Class 1 and Class 10 buildings, Books 1 & 2, Department of Agriculture and Fisheries, Brisbane.
  • Standards Australia, 2008, AS 2858—2008: Timber—Softwood—Visually stress-graded for structural purposes, Standards Australia International, Strathfield, NSW.