Build A Sloping Retaining Wall

What You'll Need
Landscaping fabric
Wheelbarrow for carrying the concrete bits
Concrete units
Inter-locking concrete units
PVC drain pipe
Colored stones
Torpedo level
Gravel (3/4 inch in diameter)
Wooden stakes
Standard masonry twine

Retaining walls are commonly seen in outer landscapes. They are functional and also add to the aesthetic appeal of your garden or yard space. A retaining wall is a practical solution for sloping backyards. Retaining walls make the entire sloping surface more stable, negating any fears of the soil beds along the slopes collapsing. They also help to restrict soil erosion and prevent the garden soil from spilling onto the pavement. Retaining wall along a slope can be built with different materials. Commonly, retaining walls are made from concrete, tiles and wood. There are no strict rules regarding the construction method or the size of walls either.  Building a retaining wall isn't difficult but it is time-consuming. You can do it on your own, provided you follow some basic guidelines.

Note — you should be familiar with parameters like the standard frost depth in your area and the soil type. Different soils have varying tendencies to contract/expand when freezing or thawing. Higher frost depth means you will have to dig the foundation much deeper. Always check with the local building authorities if a permit is needed to dig the trench. Once the permit clearance has been sought, proceed.

Step 1 - Check for Water Runoff

Check areas that have established water runoff or noticeable downhill spots.

Step 2 - Mark the Area

You have to mark the area where the wall has to be built. You can drill small holes around the marked area and install wooden stakes in them. String the masonry twine among the stakes.

Step 3 - Make a Leveled Trench

Using a shovel, dig the trench along the upper side of the marked retain wall area. Throw the colored stones into the trench and level this with the rake. Using the tamper, press upon the stones to create a level surface.

Step 4 - Build the Concrete Layer

Start placing the concrete bits over the stones. Use the torpedo level for ensuring that the concrete is leveled on all sides. The concrete units have to laid and simultaneously leveled upon the stones.

Step 5 - Interlock the Concrete 

Lay the interlocking stones at about half the length of the original concrete layer, in each tier.

Step 6 - Backfilling

Start laying the landscape fabric before you add gravel as a replacement to the original soil. Using the shovel, compress at least a four-inch layer of gravel upon the concrete.

Step 7 - Check the Slope/Concrete Ratio

You should have one inch of sloping gravel for every four feet of concrete.

Step 8 - Establish Drainage

Lay the 4-inch drainpipe inside the gravel. This completes the first layer of the wall.

Step 9 - Extend the Wall

Continue placing the concrete, layers of interlocking blocks and shoveling the backfill. When the required height is reached, push down the landscaping fabric and add topsoil.

Step 10 - Check the Slope

The gradient of the topsoil should be sloping downwards.