Retaining walls help to stabilise sloped land, support the soil, prevent sinkholes on a property and add curb appeal to outdoor space. However, there's a lot of planning that goes into designing a stable retaining wall. Failure to follow the due process can lead to costly mistakes down the road. What's more, a poorly constructed retaining wall will be expensive to maintain, and it can adversely affect the appearance of your exterior space. Thus, as you plan the project, here are four mistakes you should be wary of.
Poor Choice of Retaining Wall Materials
Retaining walls can be made from various materials such as concrete blocks, rubble stone, poured concrete, brick, wood and boulders. When choosing a material, you need to look beyond visual appeal and address functionality issues. For example, if you're building a retaining wall in an area that experiences rain most of the year, you're better off with materials such as poured concrete, brick and rubble stone. Wood would most likely suffer rot or invasion by termites within a short period. Thus, choose the best material for your climatic conditions.
Failure to Account for Hydrostatic Pressure
Hydrostatic pressure refers to the pressure that the water in the soil exerts onto your retaining wall. If the wall is not engineered to withstand this pressure, it may collapse over time. What's more, if you use concrete which is a porous material, it may allow the water to seep through. This will also compromise the structural integrity of the retaining wall. Therefore, proper planning is required to ensure the wall is relieved of hydrostatic pressure.
Poor Drainage Behind the Retaining Wall
Just like hydrostatic pressure, drainage issues can compromise the stability of a retaining wall. Remember, both surface and underground water require proper drainage. Drainage options include pouring a layer of backfill gravel, installing perforated pipes or using footer drains to keep water level underneath the retaining wall. These solutions also help relieve hydrostatic pressure and preserve the stability of the soil supported by the retaining wall.
Exertion of Excess Weight on the Retaining Wall
The higher your retaining wall is, the more the weight it will have to withstand. If there is too much weight behind the wall and inadequate footing, the structure can start to lean. Thus, factor this into your design plan, if there's a lot of soil behind the wall, you need to provide adequate footing for support. High walls may even need anchors and tiebacks to offer extra support and protect them from leaning and crumbling.
At a glance, retaining walls look like they don't require much planning. However, there are unforeseen issues that can cause trouble in the future. As you plan your project, discuss these mishaps with a residential retaining wall contractor and come up with ways to address them!