Every retaining wall is unique so they all require an experienced tradesperson to build them.
You must start with a strong foundation. The footing has to be the right size for the material you are about to retain. Then you need to use the right construction method for retaining.
1. Assess the area
In our trade we spend a lot of time learning about the different materials encountered when digging foundations/ footings for retaining walls.
Below are a few examples of subsurface materials we encounter on a daily basis
- Clay: Can swell in wet weather and shrink in dry periods.
- Sand: Once you get about 2 meters down into sand it becomes quite stable.
- Shale: This is one of the better options to lay footings in.
- Rock: Bedrock is stable.
2. Consider the zone of influence
On sloping blocks you have to take into account the zone of influence. In short, the zone of influence is the amount of pressure the materials being retained will put on the wall. Depending on the materials used to backfill the wall, they will all exert different pressures. If this becomes an issue we would then engage an engineer to design the footings and wall.
3. Select materials
At Northern Suburbs Retaining Walls, we work with a number of materials including (and not limited to) Tasman blocks, Heron blocks, Sandstone, Timber and Besser Blocks.
I prefer besser blocks for the simple reason that’s what they are made for. They are made to be laid and steel placed through them horizontally and vertically then poured with concrete leaving a solid reinforced concrete wall. This is my preferred method for building retaining walls.
4. Ensure proper drainage set-up
For details on proper retaining wall drainage set-up, you can view our post here. We always back fill our retaining walls with gravel. This allows any surface water to drain freely through the gravel down to the agg pipe at the base of the footing, and out from behind the wall to prevent any water pressure build up. One of the key factors for a retaining walls longevity.
Every job is unique and done right from the start, we can create the perfect solution to suit any situation.
It is essential to use qualified tradesman to build any retaining walls you may require.