Want to learn how to build a retaining wall? Keep reading to learn the installation process required to build a beautiful Retaining Wall that will last for years to come. We’ll cover everything you need, retaining wall blocks, including tools, layout, equipment, base preparation, gravel selection, stacking, backfilling behind the wall, and installing the capstones (marking & cutting).
Before we begin in most areas retaining walls 4ft tall and over require a permit or possibly an engineered drawing to legally construct the retaining wall. In some areas, the height restriction is 6ft tall and requires an engineer to design your retaining wall. So be sure to check your local codes to see what is required of you to proceed. Once you have engineered drawings approved by the city. You can begin construction, following the retaining wall blueprints exactly.
Retaining Wall Blocks
There are a few different styles of retaining wall blocks that should be considered for your project. Some are interlocking while others require the use of concrete adhesives and locking pins to create the structural bond.
Hollow Block style and Solid Block style both have interlocking features and/or require concrete adhesive.
Hollow Blocks are just how they sound, with a hollow center and durable perimeter. These blocks are typically taller than their solid block counterpart. The average Hollow Block is 8 inches compared to 6 inches with solid blocks. The hollow center makes it a bit trickier to persuade with your dead blow hammer (small surface area to hit)
Solid Blocks are completely solid and are about the same weight if not more than a hollow block. They are easier to use a dead blow hammer to level your block during base course install.
Fascia wall systems are composed of a core unit(s) that has features allowing a face unit to attach to it, in some instances concrete adhesive can be used for a more permanent application.
Some popular providers of retaining wall products are Unilock, Techo Bloc, Belgard, and Pavestone
Retaining wall footers should be composed of at least
6 inches thick of gravel
6 inches beyond the face(front)of the block
18 inches beyond the back of the block- at least, sometimes farther
Average Footer is 3 ft wide or more by 10 inches deep
Footer drain with cloth covering or another filtering material
Anything less than mentioned above will decrease the integrity of your retaining wall project, likely failing.
Try not to disturb more soil than needed during excavation, if you do be sure to compact adequately.
Before beginning construction on your retaining wall, you should layout the planned excavation zone, the footprint of the footer, mark utilities, inspect grades and elevations.
Plan to excavate at least 6 inches beyond planned retaining wall footer
Mark utilities before excavation
Plan material staging
Where water will be directed from the footer drain
Setup grades stakes
Mark excavation zones with spray paint or stakes
Tools & Equipment
When you plan to build a retaining wall you are going to want some tools and equipment to help you get the job done. Maybe some helpers too, many hands make for light
work. Otherwise, you will likely need most if not all of the following:
Shovels-(flat and pointed)
String line & stakes
torpedo(1ft or less)
3ft or 4ft
Compactor - can be rented
Excavator- can be rented
Concrete saw- cutting blocks
Hammer & chisel