Farm Forestry New Zealand

Adding value to specialty timber

Peter King, New Zealand Tree Grower November 2013.

Good quality, dry macrocarpa clearwood now commands a premium price similar to New Zealand beech, especially in larger centres of population. However the price will obviously be affected by market conditions, as well as the availability of competing native and export timbers at harvest time.

It is also worth stating that the uses I mention are for the best ones for the highest grades. One of the biggest problems that we have in the trade is finding consistent availability of the required grades of certain species.

The market does not react to the sudden availability of particular species. For architects and designers to specify these timbers, they need to have confidence in their continual availability or they will specify more reliable imported timbers.

It is a waste of time to spend years promoting a timber if it will not be available as soon as it becomes accepted. The latest building regulations mean that timber used for exterior or structural use carry certification as to their appropriate strength and durability. This may affect macrocarpa and the eucalypts E. saligna and E. pilularis which are commonly used outside.

The competition

At present, competition for New Zealand plantation timbers is from a variety available. Natives of many species are intermittently available and are needed for clients who are matching existing timbers. These are mostly rimu, matai, kahikatea, tawa and rewarewa. There are also other minor species available from time-to-time. People currently favour recycled matai, rimu or totara as well as salvaged timbers such as totara and matai, instead of macrocarpa, eucalypts or blackwood.

Red beech, now called cherry beech by some mills, and silver beech are being continually harvested under a registered Forest Stewardship Certification scheme in Southland, and privately from the West Coast. Sales for these timbers are becoming more popular, especially as beech has been used effectively on some prominent feature projects.

Imported timbers have up to now been very good value. Oak and ash from the United States are favoured by architects because they are of good grade, consistent in supply and reasonably priced against our native timber. Tasmanian oak or Victorian ash are also popular with architects for interior fit-outs. Imported timbers from Papua New Guinea, Sabah and the North Pacific are also good value at present and the supply seems to be surprisingly steady.

Plantation species for timber tops

The following are the plantation species which we have successfully used for our Generation-4 timber tops. For us to manufacture these tops, we have to understand the species intimately, so it is a good guide to the value.

Lawson cypress

We have previously made some tops using a grade which had tight dressing knots less than 25 millimetres. This suited our lamination method of jointing and presented as an English country style kitchen, but this grade is difficult to get. I have seen two major fit-outs in Lawson cypress recently with excellent results.

It is a potentially valuable species, dries well without distortion and its natural durability gives it a potential for an above ground exterior use. The strong aromatic sent of the freshly sawn timber makes it popular for chests, fittings and furniture, but the demand is not generally high.

Macrocarpa

Macrocarpa is considered by many architects and designers to be the perfect environmental New Zealand timber. We are all familiar with its characteristics because over the years we have built everything out of macrocarpa from structures to furniture. The pale red to yellow colour and strong grain, along with its natural durability, are an important part of our culture.

Unfortunately, clear timber is becoming increasingly hard to get but dressing and rustic grades are more available. The future availability of macrocarpa and lusitanica is dependent on the success of future plantings, but it will always be needed.

Blackwood

Blackwood, Acacia melanoxylon, timber is the most desirable of the New Zealand plantation species and definitely the most dramatic. Darker timbers are popular at present and this trend is likely to continue. Australian stock is becoming increasingly expensive and long lengths of the larger sizes are impossible to obtain. Problems with New Zealand stock are always about grade. At present there is very little use for downgrade except firewood. The joinery and furniture trades need clean dark heart grades only, for which premium prices will be paid. Blackwood is a decorative furniture timber for interior use.

Logs for slice cut veneer get the best price and clean heartwood in long lengths are best. The colour varies from site to site but generally older trees get the darkest timber – a big tree is a good tree. Timber is best dried to 12 per cent moisture content before it has any real value. This is the species we can plant in abundance as it will always have a strong market appeal.

The grain structure of A. dealbata is similar to A.melanoxylon, but it is generally much pinker and has a more open grain. Good quality timber is becoming available and it takes a stain well. There is a good chance it will fit into the same market, which is for interior fittings, fitments, furniture and countertops. It should be a good flooring timber.

Eucalyptus saligna and E. botryoides

These are high value timber. E. saligna is now mostly understood by architects and designers so it is commonly used throughout New Zealand, especially in the North Island. To some extent it is a replacement for jarrah, which is also increasingly expensive and the grade is declining.

The best timber is straight-grained as even curly- grain timber usually results in checking. The colour varies from straw through to deep pink or red, but it takes a stain well, so uneven colouration can be blended for interior work. To prevent checking, it needs to have maximum 12 per cent moisture content, but good timber dries readily with a combination of air and kiln drying. E. saligna has been successfully used for all internal joinery fittings and even exterior joinery.

New Zealand ash

For national marketing reasons, we have called all the pale eucalypts New Zealand ash. This is in spite of differences in their grain structures and colours. They include Eucalyptus regnans, E. delegatensis and E. fastigata, among others. Tasmanian oak and Victorian ash also represent a group of pale eucalypts. It is very confusing for the general public who find it difficult to differentiate them, especially when we do not know which species is predominant.

In spite of the above, some clients and their architects will specify certain species. The basic rule is a big gum is a good gum, be patient and let them grow.

Elm

Elm is a traditional cabinet material in Europe and some beautiful furniture has been made in New Zealand by most cabinet makers and joiners, especially in the North Island. It tends to distort during drying, so overcutting is necessary. It needs to be properly filleted and held down with weights to minimise twisting.

It is susceptible to bugs and sapstain when wet so it needs to be made ready for drying promptly. Clean your fillet site well to get its moisture content down quickly so the insects do not get in. It will require 18 months per 25 millimetres of thickness to season. Wide flitches have the best market and can be re-sawn to suit the client. Elm stains well and looks a very good in a fine piece of furniture or in fittings.

Oak

The timber quality of oak is very dependent on the site where it is grown. It can be notoriously unstable, with large open checking which ruins the timber if it is allowed to dry too fast. If it can be properly seasoned, very good quality timber can be obtained.

A big oak, either quarter sawn or flitched, gets the best timber. The drying time will be at least two years per 25 millimetre thickness, so for 50 millimetre stock which should be overcut to 55 millimetres, it will take up to five or six years to season. New Zealand grown oak has been used for fitments, fittings and furniture but to a more limited extent than is hoped.

Black walnut

At present New Zealand stock of black walnut is very limited, so stock from the United States is generally used. It is expensive and also has grade and availability problems. There are some very good specimens growing around the country, and it is hoped that excellent timber will be available in years to come.

Peter King is the owner of Kings Woodworking Company in Carterton.