Benefits of remedial preservation of timbers used in construction

Whenever we work with untreated or treated timber products and process the timber by cutting, drilling, or notching, it weakens the treatment envelope, the strength, and the lifespan of the timber.

Even where the timber has been fully treated in-ground service, there remains the need to protect the timber (once the above actions have occurred) to ensure that timber durability is maintained over time, as it was originally intended.

Metalex restores the treatment envelope and delivers long-term protection that meets the strict requirements of the New Zealand Building Code.

Timbers that are used within the scope of the New Zealand building industry need to comply with NZS3602 Timber & Wood Based Products Used in Building – Section 2.3.5 Supplementary Treatments.

This applies equally in Construction (Building), Landscaping, or Fencing applications. In construction, whether the purpose is an outdoor timber pergola or other outdoor structure, or even if used in the main part of the main build including timber house piles, flooring bearers, exposed roofing trusses, wet areas, timber weatherboards ‘H3.1’, or any place using ‘H3.2’ timbers there is a requirement for preservation of the treatment envelope.

The very action of processing timbers used outdoors, with direct or indirect environmental stressors on them, allows a greater chance for moisture, fungus, insects, and UV light to degrade the timber cellulose fibres over time. When we look at the damage that UV can do to timber, the greying of the timber fibres, and the wear and grain profile of cut ends, it really shows how we need to improve the durability and performance of the timber. This damage can cause more water to be absorbed into the timber which in turn leads to additional issues.

A simple way to ensure that you achieve this protection is the use of Naphthenic acid salts in the form of either Copper Naphthenate (Green) or Zinc Naphthenate (Clear). Both products are equally as good at achieving the desired result; they just do it in a slightly different way, but with the same result for compliance and durability.

Remember that both the Green and Clear versions of the Metalex Timber Preservative range do the same job. They are equally as good as each other when used in accordance with the application instructions.

For more information on timber preservation or technical advice, please contact our technical team on 0800 701 080 or visit our website to see our comprehensive product range and technical data www.soudal.co.nz/products/

This Technical Tip was supplied by NZCB National Partner Soudal. Soudal are a key supplier of sealants, foams and adhesives to tradies under our iconic Gorilla brand. For over 30 years Gorilla Grip, Foam, Glues and Silicones have proven their quality, reliability and technical performance in kiwi conditions. www.soudal.co.nz