The function of a retaining wall is to “dam the earth,” so to speak – they are used to prevent erosion and slippage in areas marked by steep, sudden declines to more level ground. The overall effect is, essentially, a flattening of the sloped ground, bringing stability and greater ease of maintenance to the landform.

Retaining wall designs have many applications, from improving road safety to adding a touch of decorative accentuation to your yard or garden. The latter is the most common application for homeowners, though they frequently also serve the practical purpose of stabilizing the elements above the wall.

Building Retaining Walls: The Major Types

Broadly speaking, there are four main types of retaining walls:

• Gravity walls. This type of retaining wall relies almost entirely on its mass to resist the force of the elements it holds at bay. Most walls of this style are concrete retaining walls, since a wooden fence doesn’t have the strength to resist the force applied by steep slopes.
• Piling walls. Usually used for applications involving soft soils or cramped spaces, piling walls use tie-back anchors and are usually one-third above ground and two-thirds below ground. Most wood retaining walls take this form.
• Cantilevered walls. These walls use retaining wall blocks to form a cantilever designed to convert horizontally oriented pressure coming from above the wall to vertically oriented pressure, which is directed down beneath it. One of the advantages of a cantilevered retaining wall is that it can be built using much less material that is required to make a gravity wall.
• Anchored walls. As the name implies, anchored walls rely heavily on anchors, placed in the soil behind them, for their retaining power. Generally, this complex design is only used when the wall is expected to bear a particularly heavy load.

Decorative Retaining Wall Designs

If you’re wondering how to build a retaining wall of your own, the first thing to do is anticipate the size of the load it will bear. In most yards, it will be modest, leaving you free to consider the aesthetic as well as practical features of the wall.

Segmental retaining walls combine principles of mechanical interlock and mass resistance to create a tiered wall which looks sharp, especially in wraparound or circular forms. You can also add touches of creative flair by choosing retaining wall blocks with special textures or designs, or by creating a patterned appearance by varying the colors, shapes or sizes of the blocks you use.