Last Updated Dec 3, 2010 · Written by Kerry Finch
Not all blocks of land are located in flat areas. Some areas have a natural sloping landscape that makes it quite a challenge to create outdoor living spaces like a garden, a playground or a swimming pool. If you have such a situation in your property, a retaining wall may be necessary to create usable flat areas and to prevent erosion.
Retaining walls can be constructed using any of the following materials:
1. Timber or planks of wood. If you intend to build your own wall using timber, limit its height to a maximum of 4 feet. Wood planks are heavy and may be difficult to handle for do-it-yourself projects. To keep timber in place, you will have to secure your wall with anchors tied and buried strategically around your wall. It is best to consult an experienced contractor for the right techniques for spacing and installing your wall's anchors.
2. Interlocking blocks. Also known as "segmented retaining walls", these concrete blocks are popular because they are ready-made and easy to install. Interlocking blocks come in small and modular pieces that are perfect for curving or tall walls. Blocks are also created to accommodate drainage pipes for soil-water management.
3. Stacked stone, brick or block materials. While a wall made from pieces of stone may be quaint and can easily add visual appeal to your home, it can be difficult to construct without the help of a professional. Since you will be working with natural stones, finding materials that fit squarely with one another is going to be a challenge. Mortar work is also necessary to make a stone wall sturdy.
A brick wall is another attractive option but it may turn out to be more costly than stone or concrete blocks. A wall made out of cinder blocks is relatively inexpensive but may not be as strong as that made from concrete blocks. While the terms "cinder" and "concrete" blocks are often used interchangeably, a cinder block differs from a concrete block in that the former is a mixture of concrete and some other filling material, usually coal, making it weaker than a concrete block. To add strength to cinder blocks, you will have to reinforce them with steel and concrete.
4. Concrete material. Concrete has long been regarded as a strong and reliable material for walls. The only disadvantage that a concrete wall has is that it is not as attractive as a wall made out of stone, timber or brick components. It is best to hire a contractor for the construction of your concrete wall because the pouring of concrete requires some experience.
When planning a retaining wall, the following challenges should be considered:
Due to space issues, sometimes a car, heavy equipment or a shed may be placed close to the wall. The weight of a heavy object may add pressure to the wall making it susceptible to collapse. To keep this from happening, your engineer may specify that your contractor install additional anchors or "deadmen" to reinforce your wall.
The soil above or around your retaining wall may become waterlogged after rain. Gravity is such that the pressure of wet soil may bear against the wall and cause it to sink or slip away. Installing perforated drainage pipes in the wall can help ease the pressure coming from soil erosion or wet soil.
When wet soil freezes in cold weather, the ground can push the wall upward and cause it to break. One way to address frost heave is to build the wall on a concrete block below frost level. Ample drainage should also help to lessen the accumulation of frost.
Many councils require engineers drawings to be provided for retaining walls, so be sure to check the requirements before you begin construction.