Doug Howick

Timber Preservers Assoc of Australia

This journal shares a birthday with the Australian wood preservation industry, for while TimberTrader News has been with us for 20 years, our timber treatment sector is now 50 years old.

So let us briefly look backwards to enable us to predict where wood preservation is heading in the next few years.

Timber treatment has a long history but has only become the basis of an important industry since the development of vacuum-pressure impregnation techniques 150 years ago and the successful formulation of CCA waterborne preservatives in the 1930s.

Timber Treatment Industry

Dip treatments to immunise the sapwood of eucalypt hardwoods from attack by the Lyctus borer were carried out in Australia in the 1930s.

However, an ‘Australian Wood Preservation Industry’ really began twenty years later in the 1950s.

Following the formation of Hickson’s Timber Impregnation Co (Aust) Pty Ltd in 1955, that company opened Australia’s first commercial pressure treatment facility at Grafton, NSW in early 1957.

The preservative was creosote and the product was treated poles for transmission and telegraph lines.

The timber treatment industry soon became a significant sector of the Australian forest products industry.

In less than five years there were 36 commercial plants using a variety of preservative formulations and application techniques to produce a variety of treated timber products.

Today, there are more than 160 treatment facilities in all states and territories.

Per capita consumption of treated timber products in Australia is about 0.07 cubic metres per annum.

This is almost twice that of the UK, similar to that of the USA but only about one quarter of that of New Zealand.

Given the comparatively low per capita consumption and a similar “outdoor” culture to New Zealand, the treated timber market in Australia may be poised for considerable expansion.

This is particularly so in view of the declining supply of naturally durable species, an expanding plantation softwood resource and comparatively low raw material costs.

However, it is now relevant to determine whether any other factors are expected to impinge upon such a relatively optimistic forecast - and there are at least two.

These are the growing calls for wood-use reduction and an increasing concern about products that contain “chemicals”.

Let us consider each of these in turn and decide whether or not they could be used to benefit the forest-based industries.

Wood-Use Reduction

We frequently hear the call to reduce wood use as a building material and substitute it with so-called “environmentally appropriate alternatives.”

Just what are these alternatives?

The only viable substitutes for wood as a building material are steel, cement, plastic and bricks. All of these materials require a great deal more energy to make than wood.

Why? Because wood is renewable and is made mainly with solar energy in a factory called the forest.

All these substitutes are non-renewable and have severe negative environmental impacts of their own.

But most significantly, because they require more energy, they inevitably result in more carbon dioxide emissions from fossil fuel use and are therefore contributors to climate change.

All resource use has environmental impacts but wood is the most renewable material we use and forestry is the most sustainable of all the primary industries that supply us with our materials.

The use of timber as a raw material is an issue that has captured the imagination of a concerned middle-class that previously felt powerless to assist in controlling the environment.

However, the significant environmental impact of non wood products is rarely recognised.

Some useful statistics which came across my desk recently show that:

It takes 450 kW Hours to produce 1 tonne of wood, 10,000 kW Hours to produce 1 tonne of steel and 38,000 kW Hours to produce 1 tonne of aluminium.

An average house timber frame locks up seven tonnes of CO2.

An average steel frame emits 11 tonnes of CO2.

Preservative Chemicals

There is no doubt that in the ten years since the oganochlorine pesticides such as dieldrin and chlordane were withdrawn from use in Australia, the issue of termite infestation of building materials has increased in importance and public concern.

However, properly treated timber frames will not be attacked by termites.

Increasingly, house frames are now treated, several new products and processes have been developed to meet the demand and they provide a cost effective means of protection.

Not only are house frames treated, there are many other applications for treated timber - fencing, decking, flooring, pergolas, lattice, cladding, landscaping timbers, retaining walls, poles, piles and more.

Wood preservation has been defined as “any practice designed, intended or expected to prolong the life of timber in service”. Preservative treatment of timber makes it fit for purpose and imparts a much longer service life.

Wood-use reduction? I’m all for it! But I call it resource conservation!

What of concern about chemicals?

It is the responsibility of us all to reassure consumers about the safety of treated timber products.

Following the recent enquiry into CCA treated products by the Australian Pesticides and Veterinary Medicines Authority (APVMA), the Australia-wide enHealth Council that speaks for all States on health-related matters, stated that “. . . there is no evidence that existing CCA treated timber structures in parks and throughout the community pose a risk to public health, or that replacement or removal of these existing structures is warranted.”

Furthermore, recent use of environmentally benign synthetic pyrethroid insecticides has enabled the development of effective and low cost termite repellent timber framing treatments.

Conclusion

If a novel building material with all the properties of treated timber had been invented just a year ago, it would have been hailed as an example of the way ahead in the 21st Century.

It is - and it grows on trees. THAT’S EXCITING!