What are Retaining Walls?
Retaining walls involve the use of strategically placed material to hold soil/sand in place. Retaining walls can be made of many materials including concrete, stone/rocks, landscape timbers and man made block systems such as techno-block. No matter what the material used the key to building a retaining wall is proper preparation and installation.
The height of a retaining wall, (how much soil is being managed) has a direct relationship to the construction techniques being used. A one foot retaining wall holding a berm in place requires far less strength or re-enforcement than a 5’ retaining wall holding back many tons of soil. Also, water always needs to be considered in building a retaining wall.
Drains, either at the bottom of the wall, or a french drain system described earlier, near the top of the wall to divert water from soaking the soil behind the retaining wall are essential in some cases. Many tons of weight can be added to the soil behind a retaining wall if the run off from rain is not managed. Water will also wash out sand and find ways around or through a retaining wall making the soil behind it unstable.
The choice of material being used to build a retaining wall really speaks to many factors, the aesthetics of the wall, the strength of the wall and the cost. For example, a landscape timber wall is the easiest to build and reinforce. A stone wall can be much more expensive in materials and labor but provides a very different look.