Your Store
Change Store
Use current location
-
from
stores found
from
stores found
Features
PLACEMAKERS
Pricing will be shown based on this store.
Opening Hours
![Your complete guide to building a concrete block retaining wall]({"1201":"/medias/sys_master/root/hf0/h6a/11865965527070/concrete-block-retaining-wall-banner/concrete-block-retaining-wall-banner.jpg"} "Your complete guide to building a concrete block retaining wall")
Building a Concrete Block Retaining Wall
The Complete How To Guide to Building a Concrete Block Retaining Wall
Before you begin
A retaining wall is a great way to improve the look of your lawn and garden. It can be a beautiful feature as well as the perfect way to create a flat lawn on a sloping section.
However, because retaining walls have an important job to do, we advise you to call in an expert for any wall over 900mm high.
The Law
Before you start any landscaping or building project, it’s important you make sure the finished job will comply with the building code and council regulations. For full information on the regulations applying to your area, consult with your local council.
Let’s Make a Plan
Do a scale drawing of the area that you want to retain. From that, estimate the quantities you need. Remember some extra materials will be required for cutting, depending on the size and shape of the area.
In this article:
Materials
Buy all your retaining wall blocks from one place and from the same batch if possible, to avoid differences in colour that can result from different batches. Blocks may also display a “whitening” effect otherwise known as efflorescence. This is a characteristic of many masonry products and does diminish over time.
If you can’t buy all blocks from one batch, mix the units up before laying. If you have any trouble working out the quantities of the blocks you need, PlaceMakers offers a free estimation service.
Like any building job, you’ve got to get the foundations right. A large retaining wall will require large volumes of materials.
There are three main materials: retaining wall blocks, base course material & drainage aggregate.
Range and Styles
Firth retaining wall blocks feature a unique rear lip to eliminate guesswork, speed installation and deliver a uniform setback.
Ezi Wall® is a two-piece system with a split face texture that gives great design flexibility.
| Ezi Wall Block | 160/120 x 140 x 125mm, weight 5.5kg |
| Ezi Wall Capper | 160/120 x 140 x 125mm, weight 5.5kg |
| Available in colour: Rockface, Volcanic Ash & Onyx | |
Sedona Stone® has straight & bevelled keycut face texture that gives great design flexibility.
| Sedona Stone | 200 x 135 x 100mm, weight 5.4kg |
| Available in colour: Rockface | |
Garden Wall® has straight & bevelled, split face that enables construction of inside curves, outside curves & straight walls.
| Garden Wall | 300 x 230/215 x 100mm, weight 13kg |
| Available in colour: Rockface | |
Country Manor® has keycut face texture that enables construction of inside curves, outside curves & straight walls.
| Small Unit | 100/150 x 250 x 150mm, weight 11kg |
| Medium Unit | 250/300 x 250 x 150mm, weight 18kg |
| Large Unit | 350/400 x 250 x 150mm, weight 27kg |
| Capping Unit | 250/300 x 280 x 75mm, weight 12kg |
| Available in colour: Rockface | |
Getting Started
Excavate
Dig out the area behind where your wall will go to allow for backfill. Then dig a trench along the line of your wall’s planned base to the width and depth shown in the table (see Fig.1 below).
| System | Width | Depth required | Maximum height in meters |
| Ezi Wall® | 300mm | 150mm | 0.5M |
| Sedona Stone® | 300mm | 150mm | 0.5M |
| Garden Wall® | 450mm | 150mm | 0.7M |
| Country Manor® | 550mm | 200mm | 0.65M near vertical |
| Country Manor® | 550mm | 200mm | 0.95M 9.5° batter |
| Country Manor® | 550mm | 200mm | > 1.0M specific design |
Preparing a Level Base
Compact the soil in the base of your trench. Then add compactable base course (fine gravel) to the trench and compact until firm and level (for Firth Ezi Wall® / Sedona Stone® /Garden Wall®) to a depth of 150mm. For Country Manor a depth of 200mm is required. Check this both ways with a level and stringline to make sure your wall will be built on a good foundation (see Fig.2).
The First Layer
Getting the first layer perfectly level is critical to the accuracy of your wall. For Sedona and Garden Wall, chisel the locator lips off the blocks for the first layer prior to laying. Place the first layer of blocks on the prepared base, making sure that each block is in full contact with the base course and level from side to side and front to back. Stringline the back of the first layer to verify straightness. On sloping sites always start from the lowest point and work upwards (see Fig.3).
Preparing Drainage
If the wall is going to be over 3 layers, place a drainage coil (65 or 100mm diameter) behind the first “above ground” layer of the wall. Extend the coil away from the wall to ensure good drainage. Connect the coil to the nearest silt trap.
Laying & Backfilling
Make sure the top of each layer of blocks is perfectly level and free of aggregate and soil before laying the next layer of blocks. Lay subsequent layers of blocks by pulling each unit forward so that the rear lip engages with the blocks below. Each unit should be offset by half a unit below to maintain a “running bond” pattern.
As each layer is finished, backfill with free drainage aggregate extending out 150mm for Eziwall/Sedona Stone and Garden Wall. 300mm for Country Manor and compact. Do not use topsoil or clay material as backfill. As you build your wall, fill the cavity behind it. Ensure all cavities within each unit and gaps between are filled with free drainage aggregate. Backfilling and compaction should be carried out in 150mm to 200mm layers (see Fig.4).
Final Touches
Once your wall reaches the desired height, use the compactor to f irmly compact and fill behind the wall. Do not use the compactor on the wall itself. If using Ezi Wall®, affix the capping units to the top of the wall using a building adhesive. If using Country Manor® use the capping block and pins. If you plan to have a garden level with the top of your wall, backfill and compact to below the desired depth of your bed then add topsoil to the wall level (see Fig.5).
This article has been produced with proper care, however the advice offered within is general in nature. PlaceMakers is not responsible for the application of the advice offered and takes no responsibility for the accuracy or completeness of it. PlaceMakers will also not be liable for any consequential loss howsoever arising from the use of goods sold, nor for any loss caused by defective or inadequate structures in which goods are incorporated.
Popular Retaining Wall Products
Your local PlaceMakers team can help source what you need to get the job done!
Why are products marked Direct from Supplier or POA?
These products are ordered directly from the supplier or another branch for you. Our branch team will call you to confirm if we can source the product and let you know delivery time frames and costs (if any).
Once you accept this you will be provided a payment link to complete your purchase.
Here's what we'll do for you:
- This product is not currently sitting in your local store.
- Request this product by adding it to cart and completing check out.
- You will not be charged today.
- Next, your local team member will give you a call to help order it in, just for you.
These items are specifically sourced for you, and cannot be returned unless faulty, read more.
Alternative Products (1)
These products are similar and available as another option if your original product is unavailable.
Cottage Garden
Learn how the owners of a 1940’s cottage garden in Waiake, Torbay, transformed their wrap-around coastal garden into a low maintenance retreat.
Planter Box Project
Learn how Dean McGowan, a DIY enthusiast and PlaceMakers team member, recently built this solid and multi-tasking planter box.
Vulcan Deck Lake Tarawera
Vulcan Decking was selected as a local sustainable timber decking option because it is hardwearing and endures the test of time.
Building a Timber Retaining Wall
In this guide, we'll take you step by step through the process of building a basic timber retaining wall, with tips and tricks to help you achieve professional results.
Landscaping Catalogue
At PlaceMakers we're well equipped to turn your landscaping dream into a reality. We have a comprehensive range of trade quality products and offer helpful advice.
