Better Retaining Walls: Construction Advice

30 November 2016
 Categories: Construction & Contractors, Blog

When levelling ground off for a construction project, perhaps to install an outbuilding or to build a terrace that extends into your garden, it is often necessary to prevent the earth that you have shifted from falling back with a retaining wall. On hilly land, there may be a cutting that has been made into the slope which requires a professional engineer to design a retaining structure of sufficient strength. For more modest projects, however, a retaining wall is usually only a few bricks high and can even work as a step up to the next levelled-off area, if designed well. Unfortunately, many home-made retaining walls at even this modest height fail to last. What should you know before constructing your own?

Dig Down

Having achieved levelled-off earthworks that are flat from one side to the other means that you are ready to start building your retaining wall, right? Well, no. If you simply start laying breeze blocks down with a mortar onto the bare earth, then the ground could subside beneath them down the line, ruining the wall. In order to make your retaining wall more resistant to the sideways forces that it will be faced with, it is necessary to dig foundations. Offering a sound footing for the wall construction above, the foundation should be built to last. Most reputable concrete contractors will offer concrete pumping services which mean your foundations are solid and durable. What's more, the job is done quickly when pumps are used allowing you to make progress with the next stage.

Build Across

If you choose to make a retaining wall from a single layer of bricks, stacked up one on top of the other, then the wall is likely to be weakest in the middle and could give way. Instead, arrange your brickwork at a slight angle so that the retaining wall is thicker at the bottom than it is at the top. This way, the wall will stand up to the greater sideways forces which might overcome it lower down. Add a reinforcing buttress in the middle of the wall, too, so that the entire span is strengthened. Sloping walls, that lean into the hill they are holding back, are much more durable than ones which go straight up, such as the vertical wall of a house, for instance.

Finishing the Wall

As the wall is going up, it is advisable to back fill the earth behind it as you proceed from one side to the other. Remember to add cap blocks to the top row of a retaining wall fixed in place with mortar so that you get a nice finish and that water runs off effectively, another potential source of problems.