How to Build a Concrete Retaining Wall on a Slope?

How to Build a Concrete Retaining Wall on a Slope?

Retaining walls provide a vital boost to anyone looking to organise their garden, or have been commissioned to organise a public space. In addition, it can also make an area safer, especially if there is a slope. But does a slope make it more difficult to build a retaining wall?

In this blog, we will answer the question ‘How to make a concrete retaining wall on a slope?’

At PPC Concrete Products, we are here to provide solutions for your construction needs, from the person working their own part-time project, to commercial clients, and everyone in-between.

Monthly construction output had risen an estimated by an 1.6% value in June 2023, and we would like to think our accessible concrete products had a small part to play by giving our clients easy access to reliable and easy-to-use construction solutions.

The importance of retaining walls

How Do I Build a Retaining Wall on a Slope

Have you ever seen a wall that only has depth in front of it, but behind it is grass or soil? If so, you’ve likely seen a retaining wall. Retaining walls work by levelling land to an area it wouldn’t naturally level at. It is done by introducing a wall in front of it.

This wall would need to be dug in order to have any sort of stability. This is regardless of the size of the retaining walls.

What size is a retaining wall?

Retaining walls can be incredibly low, or high, it is completely dependent on the environment it will be placed in, along with the reason for erecting it in the first place. It can be put in gardens that have small or long, gradual slopes, or in public areas or parks that have a hill that is an inconvenience.

Retaining wall benefits

Aside from optimising space, retaining walls can be used to…

  • Prevent soil from collapsing or eroding.
  • Hold back earth for a long time, without much maintenance required.
  • Provide protection for a building (e.g. if a house is located on a higher platform, and it is in danger of collapsing after a flood or earthquake.
  • Offer protection for your natural vegetation.
  • Improve the appearance of your garden landscape, which therefore boosts the value of your property.
  • Help create a seating area in your garden, which will be comfortable and relaxing.
  • Allows you to put raised planters on top of the retaining wall, which adds beauty and colour to your garden.
  • Help reduce run-off of water after storms.
  • Eliminate piles of dirt, debris, or sand, which look unsightly.
  • Help divert rainwater, which can be utilised in your home or garden.
  • Prevent sinkholes, which will damage your landscape structure.
  • Be used for flood control- as you can incorporate drainage pipes into the wall, for drainage and water control.

How to build a concrete retaining wall on a slope?

Create a retaining wall today

When it comes to building a concrete retaining wall on a slope, it is best to consult experts, especially if you have never done it before. That being said, it can be done on an individual basis. Here are some key factors you need to keep in mind.

  • Start with the slope, where exactly on the slope do you want the retaining wall to take effect? The answer to this may affect how deeply you may need to dig for foundations and backfill, and the size of your wall itself.
  • Will you be putting stairs as a feature in this retaining wall? If so, you will require more concrete blocks to create the stairway.

Regarding how to build a concrete retaining wall, here is a very simple breakdown of the processes you have to follow to ensure you have a perfect concrete retaining wall.*

*Please note that this is an oversimplified guide, and is not taking into consideration the individual factors that can occur in your building of a concrete retaining wall.

  1. Dig accordingly – The height of your wall will determine the depth you will need to dig.
  1. Level the base – Although this generally isn’t necessary when using concrete blocks, it is always a good idea to still level the base as much as possible. Remove any stones or rocks/debris that prevents the foundation from being flat. Compact the base beforehand if necessary.
  1. Lay the first blocks – Make sure these blocks are in line as they are being placed, using a rubber mallet to ensure they are levelled with each other.
  1. Stack the blocks – If you are using our interlocking concrete blocks you do not require the use of mortar to bind these blocks together, as they can interlock with each other via in-built studs and recesses.
  1. Backfill — As you are stacking your blocks, be sure to add the appropriate amount of backfill as you have completed a level of block placements. Using crushed gravel is the usual material for this. Gravel backfill should be between 8–12 inches thick.
  1. Add the flat top blocks – Flat top blocks are our interlocking concrete blocks that are designed to be at the top of a structure made with our blocks. They contain no studs at the top.

When should I go to an expert for a retaining wall?

We believe you should consult an expert immediately if you have no experience in constructing retaining walls. This is because an expert can not only point you in the right directions of suitable materials, but can also provide the service to erect the wall correctly.

Alongside this, the fact they are likely to have the equipment necessary, saves you the effort of renting additional equipment if you were to do it yourself. For an expert, you generally have to pay for the required resources in addition to the labour costs, and sometimes, consultation.

Are there any disadvantages to a concrete retaining wall?

What else can retaining walls be made from?

It can be argued that concrete retaining walls do have some disadvantages. But this is dependent on your specific case. Here are some factors that people would consider to be a disadvantage of concrete retaining walls.

  • Concrete blocks are made to order, so miscalculations could result in a longer development time.
  • Can’t be installed with the same level of ease by hand, specifically because they are heavier.
  • The wall has the potential to bulge or slant over time, However, this is only an issue if draining wasn’t properly set up, or if the weight behind the wall has dramatically increased and pushing against the wall.

Can I use reinforced concrete for a retaining wall?

Not exactly. Reinforced concrete is the result of concrete mix being poured over steel mesh. This increases the tensile strength of the concrete. When it comes to retaining walls, there isn’t really anywhere that concrete should be poured, unless it’s for the foundation.

But even then, It can be more expensive and complicated. Unless advised to do so, you wouldn’t have to have reinforced concrete as part of your retaining wall.

Purchase a concrete retaining wall today

Aren’t retaining walls designed to withstand moisture?

As an established supplier all over the UK, PPC Concrete Products is always happy to help, which is why we encourage you to get in touch with any questions you may have or have a look at our FAQ.

In this blog, we hope to have clearly shown you how to make a concrete retaining wall on a slope, whilst also providing additional information including construction solutions that we offer.

Take a read of our case studies to truly understand how we have provided solutions for business in the past with the use of our interlocking concrete blocks, and ultimately, how we can help you today.

Read our blog page for more insights into our passion, construction.


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