FEATURE
Preservative treated wood – a sustainable choice
By SAWPA , edited by Leon Louw
A construction material provided and renewable by nature , with predictable performance , that captures carbon from the atmosphere and locks it away for decades , with low energy demand and a feel-good appeal appreciated by almost everyone – that ’ s treated wood .
Wood is part of the bioeconomy , can be sourced responsibly , is a flexible and adaptable material that can be used efficiently and aligns with the concept of a circular economy . At the end of its life wood can be reused in an ongoing process of uses , recycling or recovery of energy . Wood is consequently one of the few truly renewable construction materials .
Wood offers a simple way to reduce the CO₂ emissions through :
• the carbon sink effect of forests ;
• the carbon storage effect of wood products ; and
• substitution for carbon-intensive materials .
Not only is the production and processing of wood energy efficient , giving wood products a low carbon footprint , but wood can often be used to substitute other materials like steel , aluminium , concrete , or plastics , which require large amounts of energy to produce .
Every cubic metre of wood used as a substitute for other building materials reduces CO₂ emissions to the atmosphere by an average of 1.1 tonnes ( t ). If this is added to the 0.9t of CO₂ stored in wood , each cubic metre of wood saves a total of 2.0t of CO₂ . Based on this , an increase in buildings whose main structural components are made of wood , will produce significant CO₂ savings as prescribed by the Kyoto Protocol *.
WOOD PROTECTION
The natural durability of wood is limited to the heartwood , but this depends on the species , growth conditions and provenance . Apart from a very few , mostly tropical hardwood species , most untreated wood is vulnerable to biodeterioration by fungal decay and wood destroying insects .
These biological agencies also degrade the sustainability credentials of untreated wood leading to early failure in service , premature release of CO₂ and economic loss , more characteristic of a linear economy than a desirable circular economy .
Commercially important wood species are typically derived from locally grown well-managed forests delivering high growth rate
ALEX AZABACHE
Wood is part of the bioeconomy , can be sourced responsibly , is a flexible and adaptable material that can be used efficiently and aligns with the concept of a circular economy .
14 AUGUST / SEPTEMBER 2021 // www . timberiq . co . za