Retaining Wall Installation
There are a few options when it comes to retaining wall installation. First, you will need to know the difference in various styles of landscape walls. A wall can be ornamental, functional, or both. Some of our retaining walls hold back massive amounts of earth and level out large areas of land. Other retaining walls simply look pretty, bordering shrubbery. We have a large selection of natural rocks and concrete blocks available to create the look for which you are searching.
Ornamental retaining walls are often used to create “raised landscape beds.” Sometimes ornamental walls are incorporated into hardscape designs or planting designs for aesthetic improvements.
A common type of ornamental wall in a hardscape design would be a free standing wall. Free standing walls technically have all 4 sides (or faces) of the wall exposed. Retaining walls, on the other hand, usually only have 1 exposed face because the other three faces of the wall are covered by the material being the wall is retaining. For the sake of keeping things simple, we will tend refer to all the types of landscape walls we install as retaining walls.
We believe that all walls should have some sort of function. Even our ornamental walls are usually built with a purpose. A wall’s function could just be to create extra seating or to delineate one area in the landscape from another, but it still has at least some function in our eyes. Rarely do we install a purely ornamental landscape wall, so all of our hardscape structures are built with function in-mind.
At each end of most free standing walls, free standing column units aesthetically anchor the structure into the landscape. Free standing column units built out of landscape blocks can be used in the construction of fencing to encompass the posts. This type of structure is commonly coupled with ornamental iron or wooden privacy fence barriers surrounding gated communities as well as at the entrance to up-scale neighborhoods. Free standing column and wall units can also be constructed out of masonry materials (brick and mortar), but this is not a service we offer. We install concrete block columns and walls, held together with special concrete adhesive products. Double-wide freestanding walls and columns can be filled with pre-mixed concrete. Once dry, a stronger adhesion than the concrete adhesive alone can be achieved
Building a Retaining Wall 101
Constructing a retaining wall is a whole lot of work, but it really isn’t all that complicated. There are a few rules and tips to remember as you proceed with each step of wall installation. Like everything else, the first step is always choosing the location and type of wall you will need. Knowing that, you would then want to choose the materials with which to construct your retaining wall. If you live in Springfield, Nixa, or Ozark, Missouri, it’s probably best to set up a free consultation from someone on our staff at this point. That way our excellent team of landscapers can advise you on making the best decision possible for your particular retaining wall installation project.
Once the materials have been selected and procured, the base for the wall must be excavated. We like to have a base that is 10% as thick as the wall is tall, and we also like to bury at least 10% of above ground height of the wall. So a 60 inch tall wall (from ground to top of the wall) would need a minimum of 12 inches excavated (6 for base material and 6 inches of buried block) and a maximum of about 18-22 inches. For every 1 foot tall a wall is supposed to be, we add about half an inch of width to each side (front and back) of the excavation area and base material. So if your wall blocks are the standard on a large size of 12 inches deep, and your wall is to supposed be 4 feet tall, the base material ought to be 16 inches wide with the wall leveled and laid on center. The reason our maximum depth ends up being between 18-22 inches is because once your minimum amount of block is buried and another entire block is buried on top of that, the wall can be stepped up by over-laying half of the last block set. The base layer of the wall does not have to run level into a hill as long as the minimum percentage of the height is buried.
The base material used in a retaining wall used is commonly pea gravel or 3/8 clean limestone gravel. After filling the excavated area with this aggregate material and compacting it well, the base layer of blocks can be laid. Sometimes it is necessary to include a drain pipe along the back of a retaining wall at the base to control water flow in more extreme situations or larger structures. Otherwise retaining walls are usually backfilled with a simple 3/4 – 1 inch clean gravel. This gravel backfill prevents top soil and backfill dirt from seeping out between cracks on the block wall, as well as allowing for the water to drain behind the retaining wall. If the water doesn’t drain properly behind a retaining wall, there is a could chance that wall will eventually fall forward from the pressure build-up of water weight behind the wall over time. Once properly backfilled with gravel, any other backfill dirt can be put behind your wall to fill in the space. Of course, a layer of quality, screened top soil usually is used to finish the top layer of fill after constructing a retaining wall. Capstones are available and can be used for aesthetics on some types of blocks. Not all retaining wall systems are designed to have capstones. This should be addressed during the selection of the materials prior to construction. After construction, it is often too late to add in a capstone if a block system without capstones is utilized for the installation of your retaining wall.
In theory, retaining wall construction is quite simple. The details and “what-if” situations that arise in the practice of installing a retaining wall are what inevitably make it something best handled by experienced professionals. By properly constructing your wall with function in-mind, our hardscapes team can ensure that your new retaining wall will serve its purpose for many years to come.