Retaining Wall for Backyard Makeover

If you’re considering a backyard makeover, retaining walls are a great way to add different layers to your yard, especially if you have sloped areas. One of the easiest walls to construct is a cinder block wall. All it takes is the right ground prep, cinder blocks, stone mortar mix, and a few tools. You can do this yourself, or get a friend to help to speed up the project. The key thing to remember is to keep things level. If not, you’ll finish the project and step back to admire your work and notice things are askew.

Step #1 – Pour the footing. First dig out the approximate area for the retaining wall. Stake out the desired length and width of the wall, and mark off with string. For our example, let's assume you are building a straight wall 12-foot long and 4-feet high. At either end of the wall area, and in the middle, dig a 2-foot by 1-foot hole. Mix cement in a wheelbarrow and pour it into the holes. This will serve as the footing foundation and will help prevent the wall from sagging. The taller your wall, the deeper you’ll need to dig your footings. It’s a good idea to check with local building codes on footing depths.

Step #2 – Setting the first row. With your footings poured, you may need to reset your stakes and string. The purpose of the string is to give you a straight line to set your cinder blocks against so you have a straight wall. Your first row of cinder blocks should be 4-inches to 5-inches below ground level. At this point, you may need to dig a little deeper or fill the trench with dirt to raise it up. Tamp down the dirt in the trench so it has a solid surface. Use a level to make sure the ground in the trench is level.

Step #3 – Pouring the foundation. In a wheelbarrow, mix the stone mortar mix. Add around 3 inches of water and pour in a small amount of the mix. Stir together with a shovel. Add more mix and water until you have a good consistency.  You can check the bag for specific mixing directions and ratios. Pour several inches of mortar into the trench. Smooth the concrete with a float so you have a level surface. Let harden overnight.

Step #4 – Laying the first layer of cinder blocks. Set a row of cinder blocks end to end in the trench. Slip a 3/8-inch spacer between each block. Mix a small amount of stone mortar mix in a wheelbarrow. Then with a trowel, apply mortar to the spaces between the cinder block. Wipe away excessed mortar so you have a smooth wall surface.

Step #5 – Add the next layer of cinder blocks. With your trowel, generously add a layer of mortar mix along the first section of cinder blocks. Set a row of blocks end to end, plumb with the bottom row of cinder blocks. With your trowel, scrape away excess mortar mix from the front of the wall. With a level, make sure the wall is level across. Continue this process row by row until you have reached the desired height of the wall. You will need to select a decorative stone material to complete the top of the wall. There are many styles to choose from.