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The environment, sustainability & recycling

Like to know what wood to use building a pergola or framing a barn? How about the difference between tung oil and polyurethane as a floor finish? How to revive decking or deal with merbau stains? Or how to meet the building code or bushfire standards? Or ask about the environmental advantages of wood or forest certification?

Q. I’m writing to you on behalf of one of our schools in Victoria who is part of the sustainable schools program. They are having some maintenance work done and some of their old weatherboards need replacing. The students noticed that the boards were not Australian and upon research discovered that they are coming from Russia. Aware of the ‘Global Miles’ and the lack of suitable accreditation they have stopped the repairs until they can source a local product. The Builder is a green builder and even he doesn’t know where they can source local product. Can you assist me in advising if there is a local product and who the suppliers would be?

Our organisation does not discriminate against imported timber - in doing so we could be in conflict with Australia's commitment to free trade between nations. However, we certainly support proper accreditation and certification of wood products. If that is lacking in the case you describe, there are locally-produced products that could be used. Radial Timber Sales produces weatherboards from silvertop ash, using a technique specially developed to maximise recovery from small logs. The environmental benefits of this process are described on their website at http://www.radialtimber.com/environment.html. Boral Timber also produces weatherboards from locally-grown hardwood and you can find out more from their website at http://www.boral.com.au/ProductCatalogue/product.aspx?product=2256. Finally, don't overlook "Weathertex", an Australian-made reconstituted cladding material made from sawmill waste and forest thinnings. For more about this product visit their website at http://www.weathertex.com.au/about.php.

Q. I am a landscape contractor. I currently have a client who has asked for a deck to be constructed using a sustainable timber. I am just after any information you could give me on what timber types to recommend to them. Thanks in advance

Presumably treated pine would be acceptable since it is sourced from plantations established for the express purpose of providing timber. In our view the production of Australian hardwoods is also sustainable, and you could choose any of the commercial species in the knowledge that strict environmental guidelines are applied to their harvesting and regeneration. Technically, most of our native timbers today come from regrowth forests. For example, the Victorian ash forests were severely burned in the 1939 bushfires, but regenerated and were then harvested for timber once they matured. After the recent bushfires the cycle will begin again. Three-quarters of the jarrah forests of W.A. had been cut over by the early 1900's (Woods & Forests Dept., Western Australia, Report 1916-17, Govt. Printer, Perth), so most of our jarrah now comes from regrowth forest. The various State forestry departments or equivalents all produce detailed reports of their activities which are available in the public domain, most of them downloadable from the net. I think you will see that a high standard of environmental management is applied. The Federal Government is required to publish a report every five years called Australia's State of the Forests Report, as part of its commitment to the Montreal Process. This provides an overview of our forest management and can be downloaded from www.daff.gov.au/forestsaustralia. Good management is backed up in many cases by forest certification, ie. externally accredited environmental management systems, the most popular scheme being the one based on the Australian Forestry Standard. When it comes to imported timbers your client might want to see similar evidence of certification by a third-party organisation such as the Forest Stewardship Council (FSC) and/or chain-of-custody certification. Your timber supplier should be able to provide these details.

Q. I am currently working on a project at uni with regards to park furniture. However I wanted to focus on sustainability, which leads me to the idea of using standard components of recycled Wooden pallets and bolts. The energy required to convert a pallet into ready-to-use timber, is it more than what is required to convert it to either particleboard, woodchips or biofuel?

Particleboard would require more energy than the other options because the process involves (a) chipping (b) gluing and (c) hot pressing. Conversion to wood chips requires only chipping, and conversion to biofuel might not require any energy at all, depending on what kind of plant is utilising the fuel, ie. it might simply go into a furnace and the net outcome is to produce energy. To turn a pallet into timber only requires the energy to run the planing machine (apart from the human energy to disassemble the pallet).

Q. I am currently working on a project at uni with regards to park furniture. However I wanted to focus on sustainability, which leads me to the idea of using standard components of recycled Wooden pallets and bolts. My question is whether the idea is feasable, and if this wood is durable enough to last as public park furniture. Another question I had was are there any other wood products that are a common problem and can be re purposed?

Quite a high proportion of pallets are re-used by industry, eg. under the CHEP pooling system (more info on the net). However, unwanted pallets could provide a resource for conversion to other uses. For park furniture hardwood pallets would be more suitable than softwood pallets - the latter use a relatively low grade of wood which would need preservative treatment for use outdoors. Of course, the pallets would need to be disassembled and each piece machined to plane it smooth, since pallets are made from rough-sawn timber, so there would be some time and effort required to convert a pallet into ready-to-use timber. Significant quantities of timber are salvaged from building sites and most capital cities have one or more companies that can supply different types of timber, so that would be another source of material you could explore.

Q. I am an accounting student, and I am currently involved in an assignment which is looking at cost savings provided when timber mills switch from conventional drying kilns, to a solar kiln. The project is a purely accounting exercise, and the provided information is not factually correct in places. The information that I am seeking is a rough amount of carbon that I can say is in a fallen log. I have spoken to a CSIRO employee, and they casually told me that a log is roughly 25% carbon. But, I need to be able to reference an information source, and I did not get his name. My research to date has revealed that techical data talks in carbon content as a % of oven dry wt. So, I have even tried to find a rough % moisture content, from which I could then say that the carbon content of a wet log is.... From this, I hope to be able to then say that if there is less waste logs, more are being milled and not left in the paddock to decay, then this amount of carbon will not be released into the atmoshpere. The CSIRO guys went into detail about how carbon is still released by the used timber,but over a longer period, and they distinguished between the woody mass and the leafy mass. I don't need that detail. Does this make sense? I hope that you can help, and any help given is appreciated. Thank you, Regards, Grahame Miller

A textbook in our library titled "Handbook of Wood Chemistry and Wood Composites" (ed. Roger M. Rowell, CRC Press 2005) states: "The major chemical component of a living tree is water, but on a dry-weight basis, all wood cell walls consist mainly of sugar-based polymers (carbohydrates 65-75%) that are combined with lignin (18-35%). Overall, dry wood has an elemental composition of about 50% carbon, 6% hydrogen, 44% oxygen, and trace amounts of inorganics". Of course the proportion of carbon by weight in a wet log will vary depending on how much water is in the log, so it's hard to give a precise figure. A freshly milled log may have 100% moisture content. This means equal parts of water and wood by weight. If dry wood is comprised of 50% carbon and we add an equal weight of water, then the proportion of carbon by weight will be halved, so no doubt that's where CSIRO got the figure of 25%. I'm not sure that many logs are currently left in the paddock to decay, but maybe that's not the point of the exercise. Regarding CSIRO's comment that "carbon is still released by the used timber, but over a longer period" that only happens if the wood is broken down, eg. by decay or burning. Stored wood that remains intact does not, of course, release carbon.

Q. On this website there's a statement that says: "There is no evidence to prove that harvesting timber from native forests has reduced overall forest biodiversity or led to the extinction of any species of plant or animal." Is this true? Where's the proof?

The statement is based on information contained in a document prepared by the Bureau of Rural Resources (a part of the Commonwealth government) and submitted to the Resource Assessment Commission's Forest and Timber Enquiry: 

'There is no evidence that intensive harvesting has caused the loss of any plant species
... [Executive Summary paragraph 7]

'Vertebrate species ... are ... with few exceptions, widely distributed ... Therefore, for conservation of vertebrate fauna it is not necessary to conserve every forest stand. Any extinctions of forest-dwelling species have been associated with non-logging factors
. ... [Executive Summary paragraph 8]

Provided appropriate environmental safeguards are implemented [eucalypt ecosystems] are able to recover from intensive harvesting and to re-develop their structural and floristic identity
[Executive Summary paragraph 10]

The full citation for this reference is: Lacey, C. J., Davey, S. M. and Harries, E. D. 1990. Intensive harvesting of native eucalypt forests in the temperate regions of Australia: Environmental considerations for sustainable development. Submission to RAC Inquiry into Australia's Forest and Timber Resources, Bureau of Rural Resources, Canberra.

The results of the RAC enquiry support the statement - and can be found in Resource Assessment Commission 1992. Forest and Timber Inquiry Final Report Volume 2A, Appendix H, environmental impacts of forest use.

 

 

 

 

Q. I want to buy bookcases made from Australian hardwood timber. The retailers I have visited have assured me that the timber they use is 'sustainable', but have been unable to supply further detail. How can I be sure the timber really is sustainable?

Maybe the retailers are just relying on the fact that all Australian timber is produced under strict guidelines. We are certainly confident that the production of Australian hardwoods is sustainable, and you could choose any of the commercial species in the knowledge that strict environmental guidelines are applied to their harvesting and regeneration. Technically, most of our native timbers today come from regrowth forests. For example, the Victorian ash forests were severely burned in the 1939 bushfires, but regenerated and were then harvested for timber. After the recent bushfires the cycle will begin again. Three-quarters of the jarrah forests of W.A. had been cut over by the early 1900's (Woods & Forests Dept., Western Australia, Report 1916-17, Govt. Printer, Perth), so most of our jarrah now comes from regrowth forest. The various State forestry departments or equivalents all produce detailed reports of their activities which are available in the public domain, most of them downloadable from the net. I think you will see that a high standard of environmental management is applied. The Federal Government is required to publish a report every five years called Australia's State of the Forests Report, as part of its commitment to the Montreal Process. This will give you an overall view of our forest management and can be downloaded from www.daff.gov.au/forestsaustralia.

Q. At school I'm supposed to be making a sustainability wise complex environment that actually does something e.g. has real solar panels that will heat up a supply of water. Would you have any tips for making it and/or sustainnablity issues? Thanks so much.

There's some good info about the sustainability of wood products if you go to our website and click on the tab that says "Environmental Benefits". Are you making a model, or doing some drawings? If you have to design a sustainable environment you could make sure you include some trees to absorb carbon dioxide from the atmosphere, and use wood to build any structures. However, we don't have any info on building a solar energy plant - our function is to tell people about wood products.

Q. Hi There, we are looking to recycle waste timber or plastic pallets in Sydney. Do you have any recommendations of companies or industries that may be disposing of this material? Thank you!

We don't know of any specific companies that are disposing of pallets, but suggest you contact CHEP. They have a website at www.chep.com.

Q. A house across the road from me was demolished over the last couple of weeks and they committed complete sacrilege by DUMPING what remained of the timber. Is there any chance that I may send you a small sample in the mail for a possible identification?

It is sad to see timber dumped when it can be recycled for further use. We have a colleague who is expert in the identification of timber, but it requires microscopic examination which can take some time. Consequently it is done on a fee-for-service basis. If you are willing to pay a fee, feel free to leave another message and we will put you in touch with our consultant.

WoodSolutions

Did you know?

About 6% of Australia’s 147 million hectares of native forests are public forests potentially available for timber harvesting. Timber is harvested from about 1% of those public native forests each year.