Building a Retaining Wall with a Terrace
One of the purposes of building a retaining wall is to prevent erosion. Soil erosion can be particularly bad on a steep incline, compared to flatter ground. The main culprits of soil erosion in your garden is weathering as a result of wind and rain. If your garden has a steep incline, then you would be better off building a retaining wall with a terrace, rather than a single large retaining wall. While a large retaining wall should only be built by an expert, a small retaining wall is a manageable job. This can also provide an attractive flowerbed option for inclines.
Step 1 – Permit
Before you start building a retaining wall, check with the proper authorities about whether you need a permit to carry out this work. Many people bypass this step, hoping that the authorities will let them keep a structure, as it is already built, however this is not a good policy. Abide by local building codes, and better be safe than sorry.
Step 2 – Design
The best way to design your project is using graph paper and pencil. Graph paper makes it easier to calculate measurements and proportions, and pencil is erasable if you make adjustments. At least 2 drawings for building your retaining wall should be made, the first being an aerial view, illustrating your garden and how the retaining wall will fit into it. The second design is the structure from a side view, and this will be used as an unofficial blueprint. Make sure you add clear measurements.
Step 3 – Foundations
The foundation when building a retaining wall is the most important part of the structure. Generally, you should have 1 inch of wall underground for every 8 inches above the ground. Dig a trench meeting the underground height plus 5 inches. Fill the trench with 4 inches of gravel and a 1-inch layer of bedding sand.
Step 4 – The Wall
You can now begin to build the wall out of retaining wall blocks. In order to build a stable wall, remember the 3 following rules: choose retaining wall blocks of a similar size and shape, make sure the joints of each layer are not aligned straight up and down, and if the wall is higher than 15 inches, reinforce it will another row of wall blocks.
Step 5 – The Terrace
A terrace is essentially a series of large steps. You have your first retaining wall, and then a level area, and then another retaining wall, etc. The easiest terrace to make is an independent terrace, and there are 2 basic specifications. First, the distance between 2 walls should be at least twice the height of the first wall. Second, the second wall should be no higher than the first wall.
Step 6 – Drainage
To keep the structure strong, drainage is important for a terraced retaining wall. Set retaining wall caps on the tops of all walls. Back fill each wall with crushed stones, like regular retaining walls, as the stone helps move water away from the wall. In addition, install drainage track, so that the moisture works its way down from the top terrace to the bottom terrace.