Retaining Walls

We are specialists in the supply of Posts, Poles and Timber for Retaining Walls, House Construction and Infrastructure works. Our stores stock a comprehensive range of rough sawn, arrised edge and TG&V finished timber, all treated to H4 or H5 for optimal durability. We carry a variety of diameters and lengths in stock. H6 which is suited to immersion in seawater or estuarine ground is also available on request.

Small Retaining Walls can make a great DIY project... in this brochure How to Build a Retaining Wall you will find great advice and information on how to build a Retaining Wall including drainage advice. Please Note: Whilst the advice and recommendations contained in this brochure have been produced with proper care, they are offered only with the object of assisting those interested in home improvement projects and ITM does not accept responsibility for the advice, recommendations, etc, contained herein.

Getting Started...
Retaining Walls perform heavy and important work. Therefore high or complicated walls, perhaps supporting several metres of bank or above a road or driveway, must be designed and constructed by experienced contractors. We can put you in contact with experienced Retaining Wall private contractors who would be happy to provide free quotations for the complete supply and construction of your Retaining Wall project.

Good Footings or Foundations
While the whole wall must be strong enough to support the load pressing against it, it’s the part below the ground that anchors it. No matter how sturdy the upper part of a wall is, if the footings or foundations are weak, there is nothing stopping it from falling over.

Good Drainage Behind and/or Through the Wall
When soil or clay on a slope is waterlogged, it is practically unstoppable. Like jelly while it’s still liquid, you need a bowl to contain it, but after it’s set, it supports itself. So, one of the main tasks required of a retaining wall is to drain water out of the bank behind. If a wall doesn’t drain well, even previously dry earth in the bank will gradually become waterlogged until it finally pushes the wall over.

The most commonly asked question we receive in-store regarding Retaining Walls is:
Do I need a permit/building consent?

The answer:
Generally, you will need a building consent if your Retaining Wall is higher than 1.5m, or has a building or driveway near the top.

You may also need a resource consent if there are significant earthworks involved.

Earthworks, particularly those involving Retaining Walls and excavations, can result in land instability. Land instability can cause considerable damage to both your property and neighboring properties, so ensure you plan your work carefully to see what consents are needed.

To discuss your requirements further of if you have any queries please contact us.


Useful Links:

Koppers Timber Treatment Guide

Auckland City Council