How to Install Retaining Wall Blocks Lip on Top or Bottom

Retaining wall blocks come in many sizes, styles and colors. There is one thing all retaining wall blocks have in common, however, and that is the lip on the underside. This lip shows you how to position the retaining wall blocks for the strongest wall possible, without using mortar. Many people become confused as to how to lay the block so the lip holds it in place. After you have laid a block or two, the process will become simple and very straightforward.

Step 1

Prepare the retaining wall trench, which the retaining wall blocks will rest in. Measure the trench's length and the length of a retaining wall block. Divide the trench's length by the retaining wall block's length to determine how many blocks will fit in the trench.

Step 2

Flip the number of blocks you determined in Step 1 upside down so the lips point up. Hold a chisel blade in the corner where the lip meets the block. Hammer on the chisel's handle to drive the chisel through the lip and remove it. Repeat this on every block to be used in the first row. This makes it easier to level the first row.

Step 3

Lay the first row of retaining wall blocks in the trench, with the side the lip was on down on the ground. Determine which of the retaining wall's ends you'll use to start laying the second row. Hold a retaining wall block with the lip edge down and on the side farthest from you. Set the retaining wall block on top of the first row of retaining wall blocks.

Step 4

Push the retaining wall block back so the lip hangs below the first retaining wall block row's surface. Pull the block forward until the lip butts up tightly against the first row's backside. Lay a second block next to the first block and position its lip tightly against the first row's backside.

Step 5

Build the third and fourth rows with the lips butted up against the backside of the retaining wall block beneath it.