How to Build a Retaining Wall With Three Different Sized Blocks

Use graph paper to map out a plan for the entire yard. Note all of the landmarks, the lot line, any planned berms and trees. Take measurements for the length and height of the retaining wall and record them on the layout.

Choose blocks that fit together. Blocks can vary in size and shape but should have some commonalities to create a pattern that can end with square corners. Rectangular blocks that are twice the length and half the height of a square block can make a pattern. Blocks that are more complex in their mathematical differences will be more difficult to fit together.

Create a pattern. Most patterns repeat every two to three courses. Layout charts may be available where you purchase the blocks. If you're creating your own pattern, start from the bottom row, forming a pattern that repeats. Work up from the first row, adding one layer at a time with repeating patterns.

Lay out the pattern on graph paper. Use scaled down measurements that are equivalent to the actual lengths and heights of the blocks for more accurate planning.

Decide how many blocks are needed based on the total length of the retaining wall and the number of blocks used per yard for the pattern.

Mark the areas where the retaining wall will stand with rope and stakes.

Excavate about 4 inches of the soil where the blocks will be laid.

Add 1 to 2 inches of sand in the trench and compact it with a hand tamper.

Install the first layer of blocks. As you lay each block, place a level on top. If the block is not level, tap a hammer on the higher end until the block is level.

Add the second layer of blocks. Leveling is not necessary with the second and third layers if the foundation layer is level.

Cut end blocks, as needed, for square edges. Score a line all the way around the block with a chisel and sledgehammer. Place the chisel edge in one of the score lines and strike it sharply with the sledgehammer to cut the rock.