What is a Retaining Wall?
A retaining wall is a stabilizing structure used to hold sloping ground in place and to prevent the erosion and the movement of soil. A retaining wall must be substantial and sturdy in structure in order to accommodate and redistribute lateral pressure caused by sloping. It is normally designed with seepage holes, which allow collected ground water to escape. This releases the additional pressure created by accumulated water and helps keep the retaining wall stable.
Several different materials can be used to construct a retaining wall. Stone and concrete are often used, and there are special retaining wall blocks crafted from aggregate materials and light concrete which are designed for this purpose. Some styles interlock, making assembly simpler, less costly and less time consuming, because each block fits securely with the next. Because the fit of these blocks is secure, they do not require the addition of mortar.
A retaining wall can be a series of "steps" or tiers, which allows for a more attractive design as well as more efficient erosion control. The design can include different types of plantings, flowers or materials in each tier to bring more texture, color and interest to the area. Aside from the aesthetic value, a tiered design also provides better erosion control by breaking down the amount of soil, and therefore pressure, held by each division of the retaining wall.
Large stones and railroad ties were often used to build a tiered retaining wall in the past. Today, there are many styles and types of retaining wall blocks, and most people choose preformed blocks. These blocks are affordable and easy to use, making other methods somewhat obsolete, unless the look of rough stone or wood is preferred.
A homeowner can build a retaining wall or have one built. The key to constructing a stable wall is making sure that it is completely level. Each layer must also be backfilled to give the retaining wall substance and to help provide good drainage. Generally, sand, stone, pea gravel or leftover soil is used as backfill.
Written by Sherry Holetzky
