{"id":4003,"date":"2017-01-01T16:15:36","date_gmt":"2017-01-01T06:15:36","guid":{"rendered":"https:\/\/ppmmagazine.com.au\/?p=4003"},"modified":"2024-03-18T13:04:01","modified_gmt":"2024-03-18T02:04:01","slug":"preservative-treated-wood-part-2","status":"publish","type":"post","link":"https:\/\/professionalpestmanager.com\/nz\/professional-pest-manager-magazine\/preservative-treated-wood-part-2\/","title":{"rendered":"PRESERVATIVE TREATED WOOD – PART 2"},"content":{"rendered":"

Part 1<\/a> of this two-part review from Jack Norton<\/strong>, secretary of the Timber Preservers’ Association of Australia, looked at wood structure and natural durability; here, Part 2 addresses timber preservation.<\/em><\/p>\n

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With wood being the primary food source for the wood eating species of termites, having a good understanding of wood structure, durability and wood preservation can be valuable information in predicting termite foraging behaviour, likely levels of termite resistance and making the correct recommendations to customers.<\/p>\n<\/div>\n

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What are the different treatment levels?<\/h2>\n

According to AS\/NZS1604, any product claiming to be preservative treated must be branded as specified in the standard (Figure 1). An important part of the brand is the Hazard Class. This part of the brand indicates the level of treatment or protection that has been applied to protect the (sap)wood for a defined service condition. Unpenetrated heartwood relies on the species\u2019 natural durability.<\/p>\n<\/div>\n<\/div>\n<\/div>\n

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Figure 1: All timber sold as ‘treated’ must show the treatment plant number, the preservative used to treat the wood and the hazard class for which the wood has been treated<\/figcaption><\/figure>\n

The higher the Hazard Class,\u00a0the greater the concentration of preservative specified in the Standard. The type of preservative that may be used for a nominated Hazard Class is also specified in the Standard.<\/p>\n

Scientifically conducted field trials (Figure 2, main image above) were used to set the levels of preservative concentration, and if wood is treated (and branded) to the levels specified in the Standard for a specific Hazard Class, it will perform as required.<\/p>\n

Preservatives<\/h2>\n

As mentioned earlier, The AS\/NZS 1604 specifies which preservative may be used for protection when the wood is treated to perform in a specific Hazard Class.<\/p>\n

All timber preservative formulations used in Australia must be approved for use by the Australian Pesticides and Veterinary Medicines Authority (APVMA). The APVMA approves the label, which sets out how the preservative may be used.<\/p>\n

Wood preservatives may be dissolved in water, oil or a light organic solvent, such as mineral turpentine. A wood preservative is classified into one of \u00a0these three main groups. The list below covers only those preservatives that are used to treat wood to the specifications in AS\/NZS 1604.<\/p>\n

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Water based preservatives are used to treat timber for a wide variety of applications, both indoors and outdoors for residential, commercial, and industrial uses.<\/p>\n