In this post, we’ll outline the groundwork for building your own retaining wall. This project might seem simple at a glance, but it actually takes a lot of precise leveling and heavy lifting to complete. If you think you’re up for the challenge, take a look at this how-to guide for building a retaining wall. If you want to DIY a retaining wall, first make sure you have all of the tools you will need; this makes building retaining walls much easier.

Retaining Walls: To DIY or Not to DIY

We’ve mentioned in a previous post (5 Hardscape Projects You Should Not DIY) that we do not recommend that homeowners and business owners DIY a retaining wall. This is because retaining walls generally have an engineered purpose: to prevent erosion and level out spaces. However, if you are simply building a retaining wall for decoration or don’t mind if it doesn’t last too long, you can attempt to DIY your own with the following steps. 

Keep in mind that professional hardscape experts have designed and built many retaining walls and can help build you something that will last a long time. If you’d rather have a professional wall built, get in touch with one of our Hardscape specialists. Furthermore, walls taller than three feet will likely require a permit and should be designed by an engineer.

Building a Retaining Wall – Materials & Steps

Materials You Will Need:

  • A metal rake
  • A spade shovel and flat shovel
  • A wheelbarrow
  • A level
  • Mason line
  • A measuring tape
  • A caulking gun and construction adhesive
  • A rubber mallet and a small sledgehammer
  • A hand tamper
  • Some gloves
  • Retaining wall blocks
  • Crushed stone for under the wall
  • Leveling sand

Step One: Dig Out the Trench

Wherever your wall will be, you will need to dig out a trench that will allow you to bury your first row of retaining wall blocks about halfway – accounting for the shallow layer of crushed rock and leveling sand that needs to go below the blocks. For example, if you’re using standard retaining wall blocks, your trench will need to be about nine inches deep and twenty inches wide. Make sure to dig the trench along where you will want the wall, including any curves.

Step Two: Fill With Crushed Rock

The next step is crucial if you want your wall to last longer than a couple of years. This base will help your wall stay level when the ground gets wet or changes in temperature very quickly. You’ll want about 6” of packed, tamped, leveled gravel before you start laying down your blocks.

Step Three: Lay the First Row of Blocks

Now, it’s incredibly important that the first row of blocks is level. As you place the stones, use leveling sand to get each block as level as possible. This will ensure that your whole wall is level when it is finished. After you lay the first row of blocks, it’s best to line one side of your wall (the inside edge) with crushed rock to allow drainage to occur more easily. The other side of your wall (the outside edge) can be filled with dirt.

Step Four: Lay the Next Layers

The next layers don’t need to be as precise, but you’ll still want to make sure there’s no dirt or sand in between your layers. This will make the blocks and whole wall wobbly. As you build up the layers, also build up the dirt and gravel along the inside of the wall. Stop before you reach the last layer of blocks.

Step Five: Secure the Last Layer of Blocks

This step is very important; securing the last layer of blocks will make sure your wall doesn’t lose any blocks. If you are using smaller, lighter blocks for your project, it’s better to use adhesive on every row. However, for large, heavy retaining wall blocks, this isn’t necessary. On your final row, use construction adhesive on clean blocks, laying them down just like before. Once all of the blocks are in, fill the inside edge of your wall with dirt, then you’re ready to go!

Dealing With Odd Spaces

If you DIY a retaining wall that needs to meet a surface and a partial block is needed, you can cut the retaining wall blocks with a chisel and mallet or an angle grinder. If, on the other hand, you are building a retaining wall into a slope, you’re going to need to alter how you build the trench. Here is a good example of how to do this.

Don’t Have the Time? Hire a Pro in Atlanta

All of this takes quite a bit more time than you might think, and it’s easy to get overwhelmed and throw your back out. It’s certainly doable to DIY a retaining wall, but it may be better for some to hire out this job and leave it to a professional hardscape expert in the Atlanta area. To schedule a consult with our team, get in touch with us today!