Is your treated timber 'fit for purpose'?
August 2020
Background to the campaign
The latest results from ‘mystery shopper’ research sponsored by the WPA, confirms that understanding amongst many users of preservative treated wood is very poor indeed.
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When asked if there was a specific treatment specification for timber in ground contact, over 90% of people surveyed said they didn’t know.
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When asked if they understood what ‘Use Class 4’ means, 72% said they didn’t know.
It’s a mistake to assume that all pressure treated wood is the same. Whilst one piece of treated wood may look very much like any other, the level of preservative protection could be very different.
That’s because the British Standard for wood preservation, BS 8417, requires that the loading and penetration of preservative impregnated into the wood is tailored to the desired end use. Applications for treated wood are therefore grouped into Use Classes, the three main being 2, 3(u) and 4.
Messaging to target markets
The challenge is how best to simplify this message whilst not losing technical accuracy. Therefore, starting this summer, WPA has launched an educational campaign in partnership with the Timber Trade Federation (TTF) & the Timber Decking & Cladding Association (TDCA).
For the fencing, garden and landscaping sector, the focus is on promoting the use of the term Use Class 4 for treated wood used in contact with or close to the ground, using the medium of the WPA’s Make Sure it’s 4 logo and communications package.
For the broader timber supply chain, the focus also includes differentiating between interior and exterior applications for treated wood – using a bold, colour coded 'Use Class 2, 3 or 4?' message and simplified product descriptions. See the full descriptions HERE.
To support the campaign three new Guidance Notes on Understanding Use Class 2,3 & 4 preservative treated wood are available for further guidance on what the most critical Use Classes mean in practice.
These include a simple explanation of what national standards require for each application, what species are most suitable, what preservative penetration to expect in different treated commodities and the necessary quality control criteria.
