In New Zealand, the standards for timber retaining walls are outlined in the New Zealand Building Code, specifically in the document known as NZS 3604:2011 Timber-framed buildings. This standard provides guidelines and requirements for the design and construction of timber retaining walls.
Some key considerations and standards for timber retaining walls include:
- Timber Selection: The standard provides guidance on the types of timber suitable for use in retaining walls, taking into account factors such as durability, treatment requirements, and moisture exposure.
- Design Requirements: NZS 3604 specifies design requirements for timber retaining walls, including the maximum allowable wall heights and the need for appropriate bracing and fastening methods.
- Drainage: Proper drainage is essential for timber retaining walls to prevent the build-up of water pressure behind the wall. The standard provides guidance on the incorporation of drainage systems, such as weep holes and aggregate backfill.
- Construction Practices: The standard outlines construction practices for timber retaining walls, including guidance on proper installation of posts, rails, and boards, as well as recommendations for joining methods and fasteners.
Regarding specific laws and regulations pertaining to Auckland, the Auckland Unitary Plan is the primary document that governs land use and development in the Auckland region. It sets out rules and regulations for various aspects of construction, including retaining walls. The plan specifies requirements related to height restrictions, setbacks, and visual impact considerations for retaining walls in Auckland.
It’s important to consult with the local council or a professional engineer familiar with the Auckland Unitary Plan to ensure compliance with the specific regulations and requirements applicable to your project. They will provide the most up-to-date information and guidance based on the specific location and circumstances of your retaining wall construction in Auckland.