Totara
Totara wood is light in weight and easy to carve. Totara heartwood is useful as sleepers and outdoor landscaping timber. Second-growth stands less than 100 years old have a high proportion of sapwood. Although heartwood has superior wood qualities, sapwood can be used for furniture, joinery, and also for exterior woodwork, as long as it is not in contact with the ground.
Description
Totara grows throughout the North and South island of New Zealand, and is most abundant in the central North Island.
It is usually found in lowland areas up to 600m altitude in the North Island, and 400m altitude in the South Island. A related tree, Hall’s totara (Podocarpus hallii also sometimes called Podocarpus cunninghamii,) grows in the North, South and on Stewart Island.
Totara can grow to 2.5m in diameter, but older, larger logs are often hollow. The trunk has a dark brown, fibrous bark that hangs in papery strips.
The heartwood of totara is an even reddish brown and the sapwood a pale brown. The growth rings are distinctive and even, and the wood has very straight grain, allowing it to be easily split along the grain. Totara wood has fine, even texture and finishes well.
With most supplies of totara suitable for timber now exhausted or in reserves, there is wide interest in establishing and managing planted totara for market and non-market benefits.
Although the harvest of totara is very low, plenty of totara is regenerating on farmland in NZ, especially Northland. Most stands range in age from 50-120 years, with average diameters of 11-25 cm and are the result of regeneration since original land clearing.
On steep hill slopes where there is a nearby seed source, totara can develop into small stands of saplings within 20 years where they are not heavily grazed or cleared regularly by landowners.
Totara have also been established as planted stands throughout the country. Generally-speaking, plantation-grown and second-growth regenerated native forest timbers can produce breast height diameters of 60cm, and small quantities of heartwood within 75 years.
This balustrade has been made from timber off a plantation of farm-grown Totara
Quick Facts
Botanical name: Podocarpus totara
Other common names:
Totara
Strength
The timber is not very strong, and the dry heartwood is brittle.
Durability
Totara heartwood is very durable in the ground; a 50 x 50mm stake would last in excess of 25 years, an equivalence to H4 Hazard class.
Finishes
Very difficult to paint, but primers are available to aid in this regard.
Working properties
Totara is easily worked, cuts smoothly across the grain and is very amenable to all machining operations including jointing.
Appearance
The heartwood of totara is an even reddish brown and the sapwood a pale brown.
Properties
Totara is easily worked, cuts smoothly across the grain and is very amenable to all machining operations including jointing. The tree is fairly soft, with a density of just 480kg/m3, however, once dried, the heartwood is very stable. Totara has green to 12 % moisture content tangential shrinkage of 4.0% and radial shrinkage of 2.0%.
The timber is not very strong, and the dry heartwood is brittle. Totara has a modulus of rupture of 62 MPa and a modulus of elasticity of just 6.4 GPa. It is neither stiff nor strong, and is therefore unsuited to uses such as large beams or joists, but when used in compression, such as a column or post, performs adequately, with compression strength parallel to the grain of 41.8 MPa.
Totara heartwood is, however, very durable in the ground; a 50 x 50mm stake would last in excess of 25 years, an equivalence to H4 Hazard class.
The natural durability is due to extractives, which also make the timber very difficult to paint, but primers are available to aid in this regard. Totara sapwood is also resistant to insect attack, including marine borers, and both sapwood and heartwood are suitable for marine environments.