How to Lay Retaining Wall Blocks

What You'll Need
Retaining wall blocks
Small stones
Wooden lathes
Wet saw

When there is the need to build up a wall along a hillside, retaining wall blocks are a great solution for a strong, durable wall. Many people use pre-fabricated wall blocks for this, but a retaining wall can be built out of many different materials. Laying the retaining wall bricks is not a difficult project, but does require that the do it yourself enthusiast work carefully, pays attention to detail, and takes the necessary preparatory steps. Here are the steps to laying retaining wall blocks in your landscape.

Step 1 - Prepare Ground

The most important step to laying out some retaining wall blocks is to prepare the ground. You will need to dig a trench that is the width of the retaining wall blocks and a few inches deep. This to place some stones at the bottom of the trench so it will drain the water away from the blocks instead of sitting in water or mud. Level out the stones so that the blocks will sit solidly on them even after there are several courses of blocks. 

Step 2 - Run String Line

Keeping a retaining wall straight is also very important to the strength of it. If you are using the retaining wall blocks to make a curved wall, you will still need to use some string as a reference point. Drive a wooden lathe into the ground at the start of the wall. Tie the end of a roll of string to it and unravel along the length of the wall. Drive another stake directly across from the original stake. Tie the string, making sure it is level, and at the right height for the first course of blocks. This will be your reference point for the first course of blocks.

Step 3 - Lay First Block

Start at the very beginning of your wall and lay the first block. Position the block so that it sits level with the string in both height and at the edge of the block. Set a level on the block and place some stones or pebbles underneath to keep it level. 

Step 4 - Finish First Row of Blocks

After the first block has been laid you can then continue along the course of the ground to finish the first row. Continue checking to make sure it is lining up with the string. 

Step 5 - Start Second Row

If you are using a retaining wall block that has built in connecting posts, then you will be able to sit the block on top of the other and continue with the wall. If the blocks do not have this system, you will need to use mortar in between the blocks to secure them together. Place the blocks in a staggered pattern (cutting the beginning ones to length) and spread mortar onto the block with a trowel. Set the block in place and wiggle it a little in its place. Continue laying blocks in this manner until the wall is complete.

Step 6 - Tie Wall to Hillside

Every few rows you should tie the blocks into the hillside with the use of a rebar or some other piece of metal. Drill a hole into the back of a block and set the rebar in place. Drive it into the hillside and position the block on the wall.