For decades, homeowners, builders and specifiers have relied on the term ‘treated wood’ to describe non-durable wood that has been turned into the durable timber of today.
Durable timber is commonly used for house framing, decks, fences, fascias, cladding and outdoor structures (among other products). However, as the timber industry evolves and environmental concerns grow, it’s time for the public and media to adopt the more precise and beneficial term: preserved wood.
While the phrases might seem interchangeable, ‘preserved wood’ offers clearer communication about the product’s function, better reflects modern preservative treatments, and helps to dispel persistent consumer concern associated with the older term.
The word ‘treated’ often conjures an outdated image of hazardous chemicals. In the 1980s and 90s, the main chemical treatment was chromated copper arsenate or CCA. Contains arsenic, right? Arsenic is dangerous, right? Arsenic is a chemical, right? Therefore, all chemicals are dangerous, right? WRONG!
Everything, and I mean everything, is made up of chemicals. The bottled water many are fond of and the food we eat are chemicals. The central fact that everything is a chemical is a fundamental concept taught to chemistry and toxicology students and most importantly it is the dose that makes the poison. This remains is a basic principle of toxicology.
Nevertheless, even though CCA is used to protect about a third of the preserved wood currently used in Australia, people are concerned when treated wood is used in residential settings.
Today, residential wood preservatives are vastly different. Since 2003, the industry has reduced arsenic for residential use, mainly by using non-arsenic-containing ingredients such as pyrethrins (originally from flowers, so it must be OK), and copper-based systems such as alkaline copper quaternary (ACQ) and micronised copper azole (MCA).
By using the term ‘preserved wood’, we shift the focus from the chemicals being applied to the result we are after: longevity, durability, and protection. It highlights the product’s ability to resist fungal decay or rot, and insect damage – the main reasons for its use – rather than focusing on older systems, which have a fraught history.
In today’s market, the term ‘preserved wood’ serves as an umbrella term that encompasses a range of protection methods, from the classic vacuum-pressure-impregnated wood to newer alternatives. It communicates that the wood has been made to last longer than its natural state, which is the core value proposition for the consumer.
Moreover, ‘preserved’ aligns with the technical language used by major industry bodies such as the International Research Group on Wood Protection and the American Wood Protection Association (AWPA) and the Timber Preservers’ Association of Australia (TPAA).
The AWPA sets the preservation standards in the US and the TPAA is heavily involved in setting the penetration and concentration standards for wood protection chemicals in this country. Adopting this term helps to foster greater transparency between the industry, builders and the general public.
In an era where consumers demand safer, more sustainable and better-performing building materials, the language used must reflect modern reality.
Shifting from the generic, historically tainted ‘treated wood’ to the descriptive, future-focused ‘preserved wood’ is a simple yet powerful change that benefits everyone by providing greater clarity and restoring consumer confidence in a vital, long-lasting building product.
