One of the most common elements of hardscaping is a retaining wall. Retaining walls are available in a range of materials—including stone, concrete, composite materials, and even wood—and serve a range of purposes in a hardscape. Retaining walls address issues of elevation and slope, add visual interest, and provide visual and physical barriers to delineate different areas of a yard.
Technically, any structure built at a change in elevation with the purpose of resisting soil pressure is classified as a retaining wall. The simplest type of retaining wall uses its own mass to resist soil pressure. These walls are built by excavating the area, installing a compacted, leveled base material, adding appropriate drainage (to ensure that water does not build up behind the wall), and carefully compacting the backfilled soil as you build the wall to the desired height. More complicated walls, like those necessary to hold back excessively loose or wet soils, require additional support in order to prevent failure of the structure. Consulting with one of All-N-1’s Landscape Architects will ensure that your retaining wall will be designed and built to last.
There are many factors to consider in the proper construction of a retaining wall. The material to be retained will determine the type of wall to build. Gravity and water are also factors, so the wall will need to be built to constantly withstand these elements. Water is the enemy of retaining walls. Retaining walls without adequate draining protection suffer from erosion of the base material and hydrostatic pressure can cause movement, bowing and even collapse. While sheer mass is adequate for most retaining walls to resist soil pressure, retaining walls over four feet tall and those that sustain heavy-use areas like driveways, parking areas, or the foundation or slab of a structure need to be specially engineered to withstand those additional loads.
Retaining walls, however, aren’t automatically relegated to the realm of the utilitarian. Well executed hardscaping can add dramatic effect to your residence. A retaining wall might provide a level area for a new patio, dining area, water feature, or garden space. These workhorses of hardscaping make other aesthetic changes to your landscape possible, and are a thing of beauty unto themselves.