This section provides information on the durability of wood, including building legislation requirements, treatment, the compatibility of treated wood with other materials, fasteners and treated wood, gluing, painting and moisture considerations, health and safety and disposal of treated timber.
In the context of building products it is reasonable to expect that, subject to normal maintenance, the product will last for a specified number of years.
The minimum performance in years is defined in building legislation and regulations.
Under the New Zealand Building Code, the term durability is more broadly accepted as implying ‘fit for purpose’ and applies to all those chemical and physical properties applicable to timber or wood-based products that may be used in a building.
Durability is often taken just in the context of hazards for timber in-service from biological degrade. However, other properties relating to timber applications and serviceability should also be considered under ‘fitness for purpose’.
In applications such as exterior joinery, the stability (resistance to deformation) may be as equally important to durability (resistance to fungal decay). Fitness for purpose considerations can therefore influence the choice of preservative treatment for a particular application or end-use.
NB: The code has changed as of April 2011 to use H1.2 for Timber Treatment for enclosed framing. Read the brochure Pink is Tough - H1.2 Frames it Right here.