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Retaining Wall Tips

Retaining Wall construction involves three key stages:
  1. Plan
  2. Design
  3. Build
If you have any retaining wall questions contact Aztec Landscapes by calling Tony on
0408 081 095 or using our online enquiry form.
We’ll provide you with our suggestions on how you could create durable and attractive retaining wall, at a cost that will pleasantly surprise you.

Retaining Wall Tips

Here are some tips to help ensure your Retaining Wall Construction goes smoothly.

1. Retaining Wall Build 


Always build on solid ground.
Materials
For base construction use a material with good compaction characteristics eg cement treated rubble. For the drain field and block cores, a clean free draining aggregate is needed. A well graded aggregate ranging in size from 0.25 – 1.5 inch and containing less than 10% fines will work for both applications. We refer to this as ‘wall rock’.
 
Retaining Wall Base Preparation
  • Excavate a trench at the location of your wall. The trench should be deep enough for a layer of level compacted rubble / wall rock a drain pipe at the back of the trench and the amount of base block required below grade
  • For walls up to 1.2m high or above seek a structural engineer’s advice re footing depth and material to be used
  • Compact cement treated road base with a mechanical compactor to 90%
  • Once compacted screed to 10mm using quarry sand to obtain perfect base
  • Place the first row of retaining wall blocks on the screeded quarry sand with the raised lip facing the front of the wall
  • Check each block for alignment and level side to side and front and back
  • Back fill around the base block and in the block cores with wall rock and pack to lock in place
 
Retaining Wall Construction
  • Clear the top of the blocks free from debris. Stack the next row of block so the seams are offset from the blocks below (most blocks have setback in place). Running bond is preferred but not required.
  • Check each block for alignment and level side to side and front and back.
  • Fill the block cores and behind the block width of 300mm behind wall with free draining wall rock.
  • Back fill remaining space behind the wall with soil/loam and compact.
  • Continue this process in maximum 200m lifts to top of wall.
Geogrid Retaining Wall Installation
 Walls above 1 metre are subject to engineer’s report
  • Install retaining wall block to the designated height of first grid layer.
    Backfill and compact behind wall to a depth equal to designed grid length.
  • Cut geogrid to designed length. Place grid on top of block starting at back of lip. Place next course of blocks on top of grid and fill block cores with wall rock to lock in place. Remove slack in grid and stake to maintain tension.
  • Place 200mm layer of backfill soil on top of grid and compact, working from front of wall to back.
  • Install additional rows of retaining wall block to next designated grid location.
  • Repeat process to top of wall. Install capping units as required.
  • Finish grade away from wall for water management.
Drainage details
Proper drainage construction will control the flow and volume of water above, below and behind the retaining wall.
At wall sites where large volumes of water will flow down to the wall install a permanent swale above the wall. On wall sites where water tables are near the wall base or for applications in high moisture environments install a sub drain and vent to existing storm water run.
Note – every retaining wall built in a water site will have its own unique site and soil conditions. These walls should be carefully designed for proper performance.
Aztec Landscapes are specialist builders that work with qualified engineers to give you complete peace of mind (view our retaining wall  gallery for inspiration)
If you have any retaining wall questions contact Aztec Landscapes by calling Tony on 0408 081 095 or using our online enquiry form.
We’ll provide you with our suggestions on how you could create durable and attractive retaining wall, at a cost that will pleasantly surprise you.