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Silver Beech

Silver Beech Silver beech is sourced from sustainably managed forests and is becoming the favoured wood to replace rimu as the prime native species.

It is excellent for turnery and cabinetry, and particularly good in brushes and dowels. It also is renowned for its steam-bending properties and was once used widely for motor body building.

Sustainability of supply

silverbeech_90Silver beech is a medium-density hardwood, occurring in the wetter montane and subalpine forests throughout the western South Island and the East Coast and subalpine areas of the lower North Island.

In particular, it is sourced from Southland’s natural and second-growth forests. The trunk is straight and cylindrical with little tapering.

Compared with other native beeches, silver beech is less dense and more easily worked, but less durable.

Globally, there are few timbers that can match the Nothofagus spp for evenness of texture in all directions.

The timber performs well where strength, combined with appearance, is required.

All New Zealand indigenous timbers are now sourced from privately owned forests.

These forests are required to be managed to exacting standards under detailed long-term sustainable management plans.

Every forest managed for timber on a sustainable basis has its own individual Ministry of Agriculture and Forestry approved Sustainable Forest Management (SFM) Plan or SFM Permit.

As credible supplies of native rimu decline to minimal levels, beech forests will move to the forefront of providing New Zealanders with sustainable supplies of quality indigenous timbers.

At present, standing silver beech supply exceeds demand.

However, this is likely to change with the increasing need for quality hardwood sawn timber.

For further information please contact the Indigenous Forestry Unit, Ministry of Primary Industries.

Summary fact sheet for Silver Beech (.pdf)

SilverBeechFloor2

Silver Beech Flooring

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Silver Beech Olympic Torches

 Botanical name: Nothofagus menziesii

Other common names: Tawhai, silver beech

Strength: View the mechanical properties for silver beech under the performance category below.

Durability: Both the heartwood and sapwood of silver beech are non-durable so it is unsuitable for outdoor applications. However, the timber can be used for interior and indoor furniture applications without the need for treatment.

Finishes: No particular considerations.

Working properties: The wood of silver beech is easily turned and shaped and, having no silica content, does not blunt cutting knives. It is also an excellent carving timber.

Appearance: The colour of silver beech varies with location and age, and between the sapwood and heartwood, but always has a pinkish to red overtone. The dry sapwood is a light pinkish grey and the heartwood pinkish brown.

 

Description

The colour of silver beech varies with location and age, and between the sapwood and heartwood. It always has a pinkish to red overtone.

Lighter colouring resembles maple (Acer saccarhum), while darker tones resemble cherry (Prunus serotina). The dry sapwood is a light pinkish grey, and the heartwood pinkish brown, slightly darker than heartwood totara. A fine, even texture and red colouring make it an attractive furniture timber, and when French-polished it can resemble mahogany. By steaming the timber for a longer period of time prior to kiln drying, a deep-pink colouring can be achieved.

The timber has wide colour variability, and, through careful selection and matching, individual boards and veneers can be chosen to give the desired end effect – either well matched or contrasting colour selections.

The grain pattern and deep lustre when polished provide a contemporary elegance to furniture and finished interior fitouts.

Performance

Durability

Both the heartwood and sapwood of silver beech are non-durable. It will not last more than five years in the ground.

Heartwood timber is resistant to preservative treatment, so is unsuitable for outdoor applications.

Although classed as moderately durable (similar to macrocarpa and redwood), this is an average durability measure for the whole species resource. Suitability for exterior applications, such as weatherboards, cannot be guaranteed because of the highly variable nature of the timber properties, depending on the source.

The wood can be used for interior and indoor furniture applications without the need for further treatment. When growing as a tree, the Platypus (wood boring) beetle can cause pinhole borer holes.

After processing, the tree is no longer susceptible to infestation by this beetle. The resulting wood, however, can be used as a feature grade in ‘antique’ furniture, flooring and picture frames, and is most suitable for villa restoration where new, freshly sawn timbers with little defects might adversely stand out.

Mechanical properties

The silver beech resource varies widely depending on location, with Southland silver beech being less dense and strong than North Island sources. However, compared with radiata pine, density within and between logs is uniform, and an outstanding feature in silver beech.

The moisture content of green silver beech wood ranges from 79 percent in the North Island to 97 percent in the South Island.

Southland beech has higher shrinkage properties from green timber, but, like all native beeches, is remarkably stable once dried.

Please note these comparative measures of strength are “laboratory” values using standardised short lengths of clear timber. These will not be the same strength properties as structural lengths of timber.

For the properties of structural length timber please see the tables under the structural design section.

For 12% moisture content defect-free timber, the following are average indicative properties*:

 South IslandNorth Island
Density at 12% moisture content (MC)585 kg/m3** 705 kg/m3
Modulus of elasticity9.5 GPa 13.0 GPa
Modulus of rupture85 MPa122 MPa
Shear strength parallel to grain12.5 MPa
Compression strength parallel to grain47 MPa
Side hardness 4.5 kN
Tangential shrinkage – green to 12% MC5.7%
adial shrinkage – green to 12% MC2.6%

*Because of the high variability in mechanical properties between sources, it is best to establish the properties of the specific source you are using from the merchant or timber supplier.

** Southland silver beech (averaging 585 kg/m3) is less dense than supplies from Westland (595 kg/m3) and Nelson (610 kg/m3), while North Island sourced material is much denser still at 705 kg/m3.

Machining

The wood of silver beech is easily turned and shaped and, having no silica content, does not blunt cutting knives.

Silver beech is the easiest native beech species to work with, and has excellent staple-holding properties.

The less dense material from Southland is the most suitable for furniture, turnery and brushware purposes, and also for flooring because it wears uniformly.

Ice cream sticks and medical spatulas are also made from beech.

Northern sources are stronger, and tougher, exhibiting excellent strength to density properties.

  • Machining – excellent
  • Turning – excellent
  • Steam bending – excellent
  • Gluing – good
  • Nailing – satisfactory with care

Considerations

There are no particular gluing and coating considerations.

Applications

Silver beech is suitable for:

  • turnery;
  • cabinetry;
  • brushes;
  • dowels;
  • handles;
  • railings;
  • furniture.

Case Study

Wanganui hospital handrails

SilverBeechHandrailJASMAX architects recently substituted a plastic handrail system in the new Wanganui hospital with the New Zealand produced and Forest Stewardship Council certified hardwood timber of cherry beech from Lindsay and Dixon Ltd. Jerome Partington – sustainability manager for JASMAX “was thrilled with the natural colour and humane appeal of the timber handrail and the way it helped link the external design features with the interior”.

Availability

The premier supplier of native silver beech timber is Lindsay and Dixon Ltd. The company owns and manages the rights to 11,852 ha of native forest of the Waitutu Holding Company in Southland, which sources timber from the Rowallan and Longwood forest blocks. The company is permitted to harvest up to 23,628 m³ of beech and other species on an annual basis – an estimated 1.8 percent of the total available forest stocking. This compares favourably with international sustainable management practices of 10 percent extraction volumes.

By purchasing FSC certified silver beech, this guarantees the specifier a legal, sustainably managed and internationally certified hardwood timber.

For detailed information on vendors supplying silver beech including their location in New Zealand, and products supplied, refer to the Suppliers Database go to the NZ Farm Forestry Association Marketplace for availability.