Termite resistant timber - dreams do come true!

posted: 17/Nov/2015

In addition to the use of Termite Management Systems, where building owners seek greater security, and additional protection for the timber building elements, it can be readily provided by the use of termite resistant timber.

The heartwood of many timber species (refer Table 1) has natural resistance to termite attack while the sapwood and heartwood of some naturally susceptible timbers can be preservative treated in accordance with AS 1604 to achieve termite resistance. "H2/H2F" level (or higher) is required to render termite susceptible timber resistant.

Timbers that are easily preservative treated include the main structural softwood framing timbers and engineered wood products (EWPs) from slash pine, hoop pine, radiata pine and Caribbean pine. The sapwood of termite resistant hardwoods can also be treated to render it immune to termite attack. The most common preservatives used to achieve termite resistance are based on naturally occurring insecticides, i.e. the pyrethroids, bifenthrin and permethrin or neonicotinoids such as imidacloprid.

The use of highly resistant, durable timber or treated timber is recommended for timber stumps, building poles and landscaping timber in direct contact with the ground.

Relevant preservative treatment requirements are:

H2F – timber treated for termites for use south of the Tropic of Capricorn and fully protected from the weather. Typically in softwood framing these products have a distinctive blue colouring.

H2 - timber treated for termites for use anywhere including north of the Tropic of Capricorn and fully protected from the weather. Typically in softwood framing these products have a distinctive red colouring.

H3 – timber treated for termites and decay for use in above ground, well ventilated, weather exposed applications. Typically in softwood framing these products have a distinctive green colouring.

H5 - timber treated for termites and decay for use in ground contact such as stumps, posts and poles.

Note: Other colours such as yellow may also be used on some products to indicate termite treatment.

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