Reprinted with permission from New Zealand Timber Preservation Council Woodmark Update, Edition 4, September 2008, to clarify how to use NZS 3605 correctly.
NZS 3605:2001 is the New Zealand Standard for timber piles and poles used in construction. It sets out the requirements for anchor, braced, cantilever, and ordinary piles to comply with NZS 3604:1999 Timber framed buildings. Both sawn and round piles and poles are covered by this Standard.
The main feature I wish to draw your attention to is to point out that for sawn piles there is a distinction between ordinary piles and anchor piles. Ordinary piles are required to carry a vertical load. Anchor piles need to resist lateral loads with or without bracing depending on circumstances.
Ordinary piles are graded to No.1 Framing visual grade under NZS 3631 New Zealand timber grading rules. These piles are most commonly available and used in timber foundation systems.
Anchor piles are subject to testing requirements to prove their strength and stiffness. The test requirements involve lateral load testing in a static test machine. The standard testing regime specifies that loads up to 4,080 kgs and held for 10 seconds be applied to anchor piles.
All timber piles are treated to H5.
Ordinary sawn timber piles are branded with a triangle brand. Anchor pile brands are distinguished with the addition of an A to the brand.
Please note the importance of distinguishing between ordinary and anchor piles and ensure that only anchor piles are used where specified. Ordinary piles cannot be substituted for anchor piles.