How to Build a Brick Retaining Wall on a Hill

What You'll Need

Brick retaining walls are a necessary structure when needing to hold back soil on a slope. Retaining walls serve the purpose to retain ground higher in elevation than the bottom of the wall. When building a retaining wall yourself, you should not exceed three feet unless you have the expertise to do so and have required all of the necessary permits and codes. 

Step 1 – Planning 

When building a retaining wall, you need to make certain you have the correct measurements. Retaining walls need to have a depth equal to the width of the wall. Your retaining wall will also need to extend backwards behind the wall the same amount of distance. So, for example, if you want a 1 foot wide retaining wall you need to start building the wall 1 foot below ground level and extend the side of the wall 1 foot.

Step 2 – Mark Wall 

Mark where your wall will be. Make sure your wall creates an “L” shape or “U” shape with a small portion of the wall extending backwards on one side or both sides of the wall. 

Step 3 – Dig 

You need to dig the base perimeter for your wall. Remember, you should dig far enough down and wide enough to keep the depth to width ratio for your wall. If you want your wall to be 6 inches wide then you need to dig a trench for the depth of the wall to 6 inches. The base of where you are digging should be nice and smooth before you proceed. 

Step 4 – Lay Bricks 

Lay the first row of bricks into the space you have dug. Lay the bricks into the center of your dug perimeter and 1/4 inches apart from each other. Now, mix your mortar according to the included directions. Apply mortar to the top of the first and second bricks. Do not apply mortar in between the bricks of your first brick row.

Leaving the space between these bricks creates a place for moisture and water to run which will extend the life of your wall. Now lay the first brick of the second brick row centered on top of the first and second brick of the first row. This will create a staggered effect of the bricks. You should continue to lay the second row of bricks in this same fashion, staggering the second row from the first row and only applying the mortar one brick ahead of where you are working to prevent it from drying.

With the second row of bricks, you do need to apply mortar in between each brick to secure them to one another. After completing the second row, you can continue to build your wall upwards to the desired height remembering to stagger the bricks from the row below them. 

Step 5 – Finish 

Once your wall is built to the desired height, you should wait at least one full day for the mortar to dry before proceeding. After drying, you can fill the dirt in around the base of the wall and fill in the ground and soil behind the wall as well.