New Zealand Pine also known as Radiata Pine, Monterey Pine, Pinus Insignis

New Zealand grown Radiata Pine is a "super soft wood" of 21stcentury. It is one of the most attractive and versatile industrial wood species available in international markets, suitable for a wide variety of end-use applications. It produces wood that is very acceptable to the construction industry. The bark is rich in tannins and suitable for use in the manufacture of adhesives; it also contains some wax, which may have possible use in water repellents. It is suitable for framing, industrial uses, posts, cladding, decking, interior finishes and trims, and everyday furniture.

Radiata does not begin to form heartwood until it is about 15 years old and forms it at the rate of one ring every two years. Most of the wood, therefore, is easy-to-dry and easy-to-treat sapwood. This is an advantage over many Northern Hemisphere conifers, which are largely heartwood.

Appearance

Has light coloured sapwood with slightly darker heartwood. Exposure to the sun leads to yellowing of both heartwood and sapwood. No special finishing techniques are needed for a uniform finished appearance.

Strength

The strength of New Zealand pine compare favourably with that of most traditional construction lumber species. Appropriate conversion processes ensure that the higher strength wood fibre near the outside of the log is sawn for structural applications.

Durability

Low level treatment such as boron is recommended to future-proof against insect attack in areas completely protected from moisture, such as furniture and the framing of internal walls of buildings. Because radiata pine is easily treated, the timber can be obtained to give appropriate durability in any of the Hazard Classes from H1 to H6.

Permeability

Radiata Pine forms heartwood at about 15 years and progresses slowly. At 30 years about 20% of the stem is heartwood. High permeability of sapwood makes it easy to dry and treat with preservatives. Heartwood is less permeable than sapwood, but dries readily and can also be effectively preservative treated.

Shrinkage and stability

Has good stability as compared to most other softwoods. From green to dry (12% moisture content) it shrinks, on an average, 3.9% tangentially and 2.1% radially. Stability can be improved by high- temperature drying or quarter sawing.

Working properties

Tests have confirmed that radiata pine machines well for most applications and compares favourably with a variety of other internationally traded timbers.

Mechanical Properties

At 12 percent moisture content, the density of radiata pine varies from 560 kg/m3 low-altitude growth sites from the Waikato northwards, to 460 kg/m3 in timber supplied from Otago and Southland. The average density figure for the whole country is 500 kg/m3.

Mechanical properties vary with density, and the presence of knots, sloping grain and other natural features. Because density increases with the distance from centre of the tree, mechanical properties follow that characterstic. Properties, particularly density, increase as ring width decreases. Typical mechanical properties for clear-grade, 30 years old material, 20mm standard specimens are shown below.

Modulus of elasticity7-10 GPa

Modulus of rupture80-100 MPa

Bending strength85.8 MPa

Compression strength parallel to the grain36.8 MPa

Side hardness (refers to indentation)3.64 kN

Shear strength parallel to the grain11.6 MPa

End hardness4.76 kN

Machining

Scientific studies consistently prove that New Zealand pine performs better than most of the world’s available softwoods and many hardwoods. Most wood products require machining in one form or another.

The machining characteristics of any wood species can be as important as its strength, hardness or durability in deciding which species is best for a given end use.

The most common form of machining is planing, closely followed by shaping and turning. Cross-cutting, boring, mortising and sanding are also common types of machining. A comparison with some North American species is shown in the following table:

SpeciesPlaningShapingTurningSanding

RadiataVery goodExcellentGoodVery good

Ponderosa pineFairExcellentFairVery good

Douglas firFairExcellentPoorVery good

Western hemlockPoorGoodPoorVery good

Applications

Treated radiata pine is suitable for the following applications:

• Structural uses;
• Decking,
• Fencing;
• Exterior cladding;
• Window sashes;
• Pergolas;
• Landscaping;
• Shingles;
• Barge boards;
• Exterior trim.

Interior uses for untreated timber include:

• Furniture;
• Mouldings;
• Trim;
• Panelling

Panel products, such as plywood, MDF and laminated veneer lumber, are also available from Radiata pine resources.