How to Build a Gabion Wall (RETAINING & FREESTANDING)

Below you will find a step by step guide on how to build a gabion wall, including both retaining and freestanding types.

Feel free to utilize the following information as a reference. If you have any uncertainties regarding the installation of your gabion wall, we advise reaching out to a Civil Engineer for guidance.

RETAINING WALL

• Experience Required: Hard
• Tools Required: Shovel, Tamper, Protective Gloves, Spray Paint, Tape Measure
• Materials Required: Gabion, Helical, Stone, Gravel, Geotextile

 

Step 1) Identify location

• Mark the location where you plan to construct your structure by using spray paint, rocks or alterative materials.

 

Step 2) Dig

• Retaining constructions must follow regulations and start 50cm below ground level.
• Gabion walls under 2m can be placed on the ground or at a lesser depth.
• For structures up to 2m, digging down 20-50cm until reaching a solid substrate is enough.

 

Step 3) 6 Degree Slope

• When retaining a significant amount of soil, ensure the hole features a 6-degree slope leaning backward.
• In the case of smaller or decorative constructions, it’s acceptable to maintain an upright edge instead of the 6-degree slope.

 

Step 4) Add Gravel

• Add a layer of gravel or basecourse measuring 20cm on top of the soil.

Step 5) Compact Gravel

• Compact the gravel by walking and stomping on it.

 

Optional) Concrete foundation

• Typically, low-level gabion walls don’t necessitate a foundation.
• However, in cases of significant groundwater or weak soil conditions, a foundation might become necessary.

 

Step 6) Geotextile

• Apply a geotextile or weed mat to the rear of the baskets to prevent soil and debris accumulation behind the structure.

 

Step 7) Unfold the Baskets

• Unfold the baskets, lifting the sides.

 

Step 8) Join the Cages

• Assemble the baskets, following the instructions.
• Use the helicals included in the kit.

 

Step 9) Fill with Stone

• Use the stone of your choice to fill the cages.

 

Step 10) Close Lids

• Close your baskets, folding down the lids.

 

Step 11) Add Second Row

• Position the second row of baskets directly above the first row, connecting them together using helicals.

 

Step 12) Fill and Join

• Fill the top baskets with rocks.
• Enhance security by connecting the baskets with helicals from front to back. Adjustments may be required by cutting some of them to fit the structure’s depth.

 

Step 13) Finished Project

• Your 2m gabion retaining wall is finished!

FREESTANDING WALL

• Experience Required: Medium
• Tools Required: Protective gloves, Wire cutters, Tape measure, Spray paint, Shovel, Hand tamper or plate compactor
• Materials Required: Gabion baskets, Helicals or Tying wire, Gabion stone, Geotextile, Basecourse, Concrete (optional)

Step 1) Measure and Plan

• Start by planning your freestanding structure and measuring the area.

Step 2) Mark the Location

• Mark the location where you plan to build with spray paint, stones or other materials.

Step 3) Dig a Base

• In case of 2m high structure, dig a 20cm deep base, or until you reach firm ground.

Step 4) Add Geotextile

• Lay geotextile on the base to prevent weeds from growing up and through your baskets.

Step 5) Add Basecourse

• Add 20cm of gravel or basecourse on the top of the geotextile.
• Alternatively, if the soil is weak, you may need to pour a concrete foundation instead.

Step 6) Compact the Base

• Compact the basecourse well using a hand tamper or a plate compactor, depending on your base size.

Step 7) Lay it Flat

• Lay the basket flat on the ground.

Step 8) Assemble the First Basket

• Unfold and lift up the sides of the basket.
• Then, start assembling by securing the corners with helicals, but leave the adjacent corners open for now.

Step 9) Repeat Assembling and Join Corners

• Repeat the process for the other cages.
• Use helicals to secure each corner and where the corners connect.

Step 10) Fill with Stone

• Fill the cages with stones.

Step 11) Close Lids

• Fold the lids down to close the baskets.

Step 12) Secure Lids, in case of 1m Structures

• For a 1m structure, you can secure the lids with helicals to finish it.
• For taller installations, leave them unsecured for now.

Step 13) Add a Second Layer

• Place the second layer of baskets on top of the first.
• Connect them with helicals at the front, sides, and back.

Step 14) Fill with Stone

• Fill the top baskets with stones.

Step 15) Close and Secure the Lids

• Then close the lids and secure them with helicals.

Step 16) Finished Project

• Your freestanding gabion wall is complete.

Foundation Guide

• 1m structure = 10cm base depth
• 2m structure = 20cm base depth
• 3m structure = 30cm base depth
• 4m structure = 40cm base depth
• 5m structure = 50cm base depth

Tips and Tricks

• Before beginning the process of how to build a gabion wall, ensure you have a detailed plan. Sketch out your structure’s dimensions and layout, ensuring it fits within your space and meets your needs.
• Opt for high-quality baskets and durable stones. This will enhance the longevity and stability of your retaining construction.
• Check the stability of the soil where you plan to build. If the soil is loose or unstable, consider consulting a professional for advice on additional reinforcements.
• Adequate drainage behind the structure is crucial to prevent water buildup and potential damage. Incorporate a drainage pipe if necessary.
• Periodically check your gabion wall for any signs of wear or damage. Addressing minor issues promptly can prevent more significant problems in the future.
• You can compact the basecourse using a hand tamper or a plate compactor as well.
• You can fill your baskets with different types of stones, or vary them, as long as they are larger than the hole size.

 

Do’s and Don’ts

Do’s

• Ensure the gravel base is well-compacted to provide a solid foundation for your gabion structure.
• Carefully follow the manufacturer’s instructions when assembling the baskets to ensure structural integrity.
• Apply geotextile fabric behind the structure to prevent soil erosion and maintain the structure’s stability.

Don’ts

• For constructions retaining significant amounts of soil, don’t skip creating a 6-degree slope. This helps with stability.
• Avoid overfilling baskets, as this can cause bulging and instability. Fill them evenly and securely.
• Don’t neglect a concrete foundation if your site has poor soil conditions or significant groundwater. It’s crucial for structure stability.
• Building a retaining structure requires time and precision. Don’t rush through the steps, as hasty construction can lead to structural issues.

 

Further Reading

• How to Install Gabion Baskets – A guide showing you how to assemble baskets.
• How to Fill Gabions – Learn how to fill cages.
• How to Lace Gabion Baskets – Step by step instructions on how to lace baskets.

 

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