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Retaining walls in gardens

Retaining walls in gardens video content

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The idea of garden retaining walls is to give you an attractive and easy to build solution. Gardens can have limited access and the wall may need to built by hand rather than using heavy plant.

You can see a selection of different designs, from gravity, cantilever and reinforced soil. All these solutions can be built by hand and DIY with some basic training.

We recommend five type of garden retaining wall, Keystone, Porcupine, Chevloc, Masonry, and Geoweb. The blocks come in a number of colours.

Block gravity walls including Keystone, Porcupine, Chevloc walls can be built up to 750mm in height, Gabion basket gravity wall can be built up to 5m in height.

Reinforced soil retaining walls using keystone, porcupine and Chevloc blocks can be built up to 3m in height. The Geoweb retaining walls can be built up to 12 in height

Soil reinforcement is laying a geogrid mat in layers, normally every other block course. Soil is laid over each layer and consolidated creating a sandwich effect. The reinforced soil stops the soil from shearing creating a mass that acts as the main retaining structure. It is important the soil is the right quality for reinforcement, we can advise during the design stage.

The images on this page are a gabion basket and a Geoweb example designs. Designs come with a detailed report, calculations, material specifications and a sketch of the wall section.

Garden retaining walls fail because they have not been designed correctly, we highly recommend your retaining wall is designed by a structural engineer. You can two design a gabion basket gravity design and a Geoweb reinforced soil design.

The question everyone want to know is how much does a retaining wall cost. To answer this question we have created a retaining wall design and price guide. The guide details all the retaining wall types on the website, provide a design guide to allow you to cost out the wall yourself, or we have created a cost table you can use to calculate a budget for your project. You can also compare the cost of different wall types. Get your copy.

We have a three step process to support you with your retaining wall project.

Step 1 – Select the right solution for your requirements and budget.

Step 2 – Design the solution for your site and soil requirements.

Step 3 – Prepare material schedule to obtain competitive prices from our supply chain.

The next step is to ask us questions and tell us about your project, we can then support you to deliver it and probabley save you some money.

 

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Precast retaining walls

Precast L-shaped retaining walls: A quick overview

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Precast concrete L-shaped retaining walls come in three different methods of construction:

  • Modular
  • Bolt down
  • Cast in

The modular type is used in material bays and is not suitable for retaining walls. While the bolt-down type is bolted-down to a designed foundation to take greater loads. The cast-in type is a heavy-duty retaining wall, and the base is cast into a raft, giving it greater strength.

Precast modular concrete retaining walls come in various finishes, plain, textured and coloured textured concrete. 

The design table for a bolt-down type retaining wall is included in the video. The design table has the wall heights at the top, the width, length, and weight of each L-shape, the foundation base width and depth, and the allowable surcharge amount.

From the design table, you can see the basic design principles, and from this information, we can carry out a cost analysis. We recommend that you watch the design video to learn more about the design process. We have put the cost analysis data into our retaining wall design and price guide, you can get all the data to develop your own retaining wall budget for all wall types within the guide.

We have included an example to work out a budget. From the designs in the table, we have created a bill of quantities and put together some costs. The budget is based on a wall over 50 linear metres long, so the wall has some scale. For example, if the wall is two metres high and one hundred metres long, that’s two hundred square metres with the rate is £254 per square metre. The table also gives you the labour, plant, and material calculations.

An L-shaped wall table of sizes and more information is available on the L shape wall type info page.

If you have a question, please use the ask a question or complete the price request form if you would like us to help you with a more accurate budget price.

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Kingpost retaining walls

Kingpost retaining wall design and UK price calculations: A quick overview

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A Kingpost retaining wall is a cantilever design. The posts are normally made from steel universal columns and are embedded into the ground.

The first step is to have the king post designed by a structural engineer. Learn more about the design process.

The soil information determines the size of the section and the embedment depth of the king post.

The technique for installing the posts is either to drive them or to vibrate them into the ground. If they’re going to be vibrated, the ground needs to be suitable for vibration.

Alternatively, the posts can be drilled in using an auger. The posts are put into the hole and then concreted in. In all cases, a piling contractor is required to carry out the post-installation work.

Once all the posts are installed, the panels are dropped into the channels of the steel posts.

The panels can be concrete or timber. Concrete panels can be plain concrete, textured, and colour textured.

Plain concrete panels are mostly used in industrial situations.

Kingposts are very handy for reinstating, repairing, or renewing existing retaining walls. Kingposts can be built very close to the existing retaining wall and don’t take up too much space. For an example, go to this case study.

The video includes a design table for the Kingpost retaining wall. They are approximate designs only. The actual section size and embedment design are carried out by a structural engineer using special software that analyses the soil data and load case. Learn more about wall engineering and design.

Kingpost retaining walls are very effective at low levels but become very expensive, over 3.5m in height, due to the section size and depth of embedment. For example, for a 3.5 metres height, the post length is 9 metres long with an embedment depth of 5.5 metres.

Every design is different. We highly recommend that you go to the retaining wall design page to learn more about the design process.

Head over to our King post wall type info page to learn more.

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Inclined retaining walls

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Stepoc retaining walls

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Reinforced interlocking block

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Gabion

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Masonry

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Criblock

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Flood defence