Everything you need to know about retaining walls

Retaining walls are key to maximising land availability for housebuilding projects as they facilitate the full use of sloped areas of ground across a site. A retaining wall holds back, or retains, the earth, effectively creating two different ground levels on either side of the wall. This helps create more usable space on land that would otherwise not be viable, whether it is for landscaping or building.  

Given their importance, this blog will explore some of the key aspects of retaining walls to help you decide which type is best for your project. We will look at the various types of retaining walls that are relevant for housebuilding projects, including modern solutions such as modular reinforced retaining walls. In conclusion, we will look at the most cost-effective, easy to install and aesthetically pleasing options. 

What are the four types of retaining walls most frequently considered for housing sites? 

The four main types of retaining walls typically considered for housing projects are: 

• Gravity retaining walls 

• Reinforced retaining walls 

• Cantilever retaining walls 

• Embedded retaining walls 

Let’s have a look at a brief overview of each type. 

Gravity retaining walls 

A gravity retaining wall uses the weight of bricks or blocks used in its construction and the force of gravity acting on those materials to hold back the pressure of the earth they are retaining. There is no additional support required for the soil. However, gravity retaining walls are limited in height, reaching a maximum of around 3m.    

Reinforced retaining walls 

Reinforced retaining walls use methods such as additional masonry or layers of geogrid to support the soil behind the wall. Consequently, they can be built much to greater heights than a gravity wall. When geogrid layers are used there is no restriction on their height. 

Cantilever retaining walls 

Cantilever retaining walls use ‘L’ or ‘T’ shaped reinforced concrete sections that transfer the vertical stress from the soil onto the base slab or footing and they can typically reach up to 5m in height. 

Embedded retaining walls 

Embedded retaining walls drive interlocking sheet piles or bored concrete piles into the ground. These piles use the passive earth pressure in the ground to retain the soil and are usually chosen when soil conditions are unsuitable for other types of retaining walls.  

What type of retaining wall is best suited for housing developments? 

Reinforced retaining walls are best suited for housing developments as they can meet the varying height requirements across a site and do so in a way that complements the project aesthetics. 

The materials used in retaining walls must be able to meet the housebuilder’s combined requirements of functionality and visual appeal. Traditionally this meant that bricks and mortar were used for reinforced retaining walls. However, modular retaining walls that use interlocking concrete blocks can meet the basic requirements and provide a faster, more flexible, and aesthetically pleasing solution that is also more cost-effective than traditional options. 

What are the advantages of reinforced modular retaining walls for groundworkers and housebuilders? 

Reinforced modular retaining walls do not require mortar to be used in their construction.  

Instead, this interlocking retaining wall gains its strength by using a combination of: 

• Friction between geogrid layers and the concrete blocks. 

• The binding action of granular aggregate filling the hollow cores in the blocks. 

• Retaining nibs on each block . 

This helps produce a reinforced concrete block retaining wall that offers a variety of benefits to a housebuilding scheme: 

• Can be built to any height required on-site. 

• Does not require specialist bricklayers for its installation. 

• Has an increased build speed when compared to the bricks and mortar alternative. 

• Is not as affected by seasonal weather conditions as those options using mortar. 

• Can save project material and labour costs when compared to a masonry retaining wall of the same height. 

These qualities make modular retaining walls, like Secura Grand, an attractive proposition for groundworkers. The added bonus for the housebuilder is that Secura Grand is available in a variety of colours and finishes that can complement the aesthetic requirements of the housing development. 

Where can I learn more about the advantages of concrete block retaining walls? 

Tobermore has years of experience helping groundworkers and housebuilders construct cost-effective concrete block retaining walls to meet both the functional and aesthetic requirements of residential housing sites. Secura Grand by Tobermore is a classic, textured block engineered for strength and available in long-lasting colour palettes. It is a simple reinforced retaining wall solution for groundworkers and housebuilders to help maximise their sites and deliver projects on time and cost effectively. 

If you would like to understand more about the benefits of using modular retaining wall solutions, we have a dedicated download available. It explains how Tobermore offers a complete support service for modular retaining walls. Alex Walther, Head of Retaining Walls at Tobermore, explains more:

“Our groundworker eBook covers the aspects of retaining wall builds that are relevant for groundworkers, aiming to help select the most appropriate solutions for their projects. It also explains the services we offer to support our customers through their projects,  from helping create tenders to selecting the most cost-effective backfill options.” 

“We have created a dedicated page for groundworkers to help access the entire toolkit of solutions we offer. This includes Tobermore’s Secura Portal, a hassle-free online tool that helps price retaining wall projects and create tenders, allowing groundworkers to analyse the feasibility of the project and putting them in a favourable position to win tenders.  We go the extra mile for our customers and have on-site toolbox talks and a construction support pack to ensure that all the knowledge and tools are available for a clean, professional installation.” 

If you have any questions about our modular retaining wall solution, please contact our sales team who will be happy to guide you through the retaining wall choices available for your project.