Retaining walls are one of the most practical and attractive ways to manage a sloping garden or a change in ground level. They hold back soil, create usable flat space, prevent erosion and can transform an awkward plot into a series of clean, level terraces. In this guide we look at what a retaining wall is, the main types available, what affects the cost, and how a well-built wall is constructed.
What Is a Retaining Wall?
A retaining wall is a structure designed to hold back soil or other material and keep it in place where there is a difference in ground height. Unlike a simple garden wall, a retaining wall has to resist the constant sideways pressure of the earth behind it, along with the weight of any water held in that soil. That makes proper design and drainage essential, particularly for taller walls.
Why Build a Retaining Wall?
Homeowners build retaining walls for several reasons. They create level lawns, patios and planting beds on sloping sites, they stop soil washing away during heavy rain, and they can add structure and definition to a garden design. On many properties they also make previously unusable areas safe and accessible, adding both practical value and kerb appeal.
Common Types of Retaining Walls
There are several ways to build a retaining wall, and the right one depends on the height of the wall, the load behind it and the look you want to achieve.
Gravity Walls
Gravity walls rely on their own mass to hold back the soil. Built from heavy materials such as stone, concrete blocks or brick, they are well suited to lower walls and are a popular choice in garden settings where appearance matters.
Reinforced Concrete Walls
For taller walls or those carrying significant load, reinforced concrete provides the strength needed. Steel reinforcement within the concrete allows the wall to resist far greater pressures, making this approach common where retaining heights are substantial.
Masonry and Brick Walls
Brick and block retaining walls combine strength with a traditional, attractive finish. With the right foundations, drainage and reinforcement, they offer a durable solution that blends naturally into established gardens and complements existing brickwork.
Timber and Sleeper Walls
Railway sleepers and treated timber are a cost-effective and quick option for lower retaining walls and raised beds. They suit informal and rustic garden styles, although they generally have a shorter lifespan than masonry or concrete.
Gabion Walls
Gabions are wire cages filled with stone. They are strong, free-draining and increasingly popular for a contemporary look, and they cope well with ground movement.
What Affects the Cost of a Retaining Wall?
The cost of a retaining wall varies considerably depending on its height and length, the materials chosen, how easy the site is to access, and the amount of excavation and foundation work required. Taller walls need engineered foundations, reinforcement and robust drainage, all of which add to the price. Ground conditions, the need to remove spoil, and any structural design or Building Regulations requirements also play a part. The best way to understand the cost for your project is to arrange a site visit and a tailored quotation.
How a Retaining Wall Is Built
A properly built retaining wall starts below the surface. The process typically involves excavating to a firm base, laying a solid concrete foundation, building up the wall in the chosen material, and incorporating drainage behind it to relieve water pressure. Weep holes and a free-draining backfill stop water building up and pushing against the structure, which is one of the most common causes of failure in poorly built walls. Taller walls may also require steel reinforcement and a structural design signed off by an engineer.
Retaining Walls Built to Last with MLS Contractors
At MLS Contractors we design and build retaining walls across Surrey, Sussex and the surrounding areas, combining sound groundworks with quality brickwork and hardscaping. Whether you need a low garden wall to create a level lawn or a substantial structural wall to manage a steep slope, our team will get the foundations and drainage right so your wall stands the test of time. Contact us today to discuss your project and arrange a quotation.