The coastal forests of NSW contain many stands of blackbutt, a versatile and durable native hardwood. Photo Forests NSW Image Library

Those familiar with the  coastal forests of NSW will be sure to recognise the native hardwood blackbutt  (Eucalyptus pilularis). The species gets its common name from the rough bark at  the base or butt of the tree, often charred black from past bushfires.

In New   South Wales, the species occurs in forests from Bega in the south  to the Queensland  border. It is typically found on slopes in the hilly country from the coast to  the Great Dividing Range.

It is a tall to very tall  tree, often over 40 metres in height and occasionally up to 70 metres tall,  with a long straight cylindrical trunk. It can also have a diameter of up to 3  metres.

The tree’s rough, fibrous  bark is only on the lower trunk, with the upper trunk and branches normally  being smooth to whitish yellow in colour. The bark sheds away in strips from  the upper part of the trunk, leaving smooth branches, often with the  ‘scribbles’ carved by insects on the bark.

If the tree can’t be  identified from a distant look, one of the easiest ways to identify a blackbutt  is though an examination of its buds and fruit – or the gum nut.
  Coastal forests featuring  blackbutt are generally high quality forests, with associated species including  tallowwoods, Sydney  blue gums, turpentine, spotted gum and smooth-barked apple.

Some of the State forests  where blackbutt is one of the top species   harvested include Broken Bago, Bellangary, Maria  River, Kerewong, Queens Lake,  Middle Brother, and Kiola.

 The timber

In coastal regions,  blackbutt is one of the highest value timbers. Foresters manage these State  forests to ensure the best possible blackbutt sawlogs grow and regenerate.

The timber ranges from  cream to pale brown, with a faint tinge of pink. The grain is straight, with  gum veins present.

 Uses

Blackbutt is a contemporary  and durable choice for flooring. It has a large variety of highlights and  features, and is sold according to appearance. It is available in various  widths and grades (for example select grade, where boards are consistent and  uniform in appearance, through to high feature grade where natural growth  features like knots and colour variations can be seen). Every floor is unique  and determined by personal preference, the way the floors are laid and  finished, and the source of the boards.

Unseasoned, the timber is  also used in general house framing, fascia and barge boards. Seasoned, in  addition to its most popular application in flooring, blackbutt can be used for  dressed cladding, decking, lining and joinery. Outside the home, it can be used  in fencing, landscaping and retaining walls.

The timber is also used  in engineering and construction in bridges and wharves, railway sleepers, poles  and piles.

Decorative use of  blackbutt include quality furniture, outdoor furniture, turnery and parquetry.

Blackbutt has also been  known to be used in boat building, agricultural machinery, structural plywood  and for making paper, especially fine writing and printing paper.

 Technical information

Blackbutt has a Janka  rating (kN) of 9 (this test measures the relative hardness of the timber – the  higher the number, the harder the timber); a Dry Density of 900kg/m3; a  Durability Class ranking of 1; and a structural rating of SD2 or SD3.

 Buying blackbutt

A number of sawmills  process blackbutt timber logs from NSW   State forests. When  buying timber, consumers are encouraged to ask about its source. Looking for  certification symbols will also give buyers independent reassurance of the  sustainability of product.

For more information  see  www.timber.net.au,  Australian Timber Flooring Association,  Wood Naturally Better.

This article appears in the Autumn/Winter 2010 edition of Bush Telegraph Magazine.