Installing a Retaining Wall

Installing a retaining wall will take some planning, as you will need to have the blocks delivered, unless you have a truck and want to manhandle them yourself. You will also need to figure out, based on the length of the wall, how much rebar will be needed. You will need two rebar poles for each hole in the cinder block.

Preparing the Footer and Rebar

Cut the rebar to the proper height. To find the height of the rebar, add 6 inches to the height of the wall. The rebar will be pounded into the ground 4 inches. It will then go through 4 inches of concrete footer. The top of the stick of rebar should be 2 inches below the top of the last row of cinder blocks.

Dig a trench for the length of the wall. Make the depth of the trench 6 inches. The width should be 12 inches. Temporarily lay the first row of blocks. Center a stick of rebar in each hole. Pound the rebar about 2 inches into the ground. Remove the blocks. Make sure the rebar is standing straight before pouring the cement. Mix the cement and start pouring the cement into the footer trench. Make the cement 4 inches thick. If you make it thinner, the cement could crack under the pressure of the retaining wall.

Allow the cement to cure pursuant to the instructions on the brand of cement you are using. If you are having a cement truck pour the footer for you, ask the workers how long their cement will take to cure.

Building the Wall

Once the cement is cured, start laying the blocks. Using a trowel, coat the footer with about an inch of mortar (use the outline of a block--the mortar does not need to go the entire width of the footer). Only coat the footer for the length of the block so the mortar does not dry out before you get to the next blocks. Center the first block on the rebar and tamp it down with a rubber mallet or your fist. Use a level to make sure the block is level. Spread mortar on the end of the first block and the top of the footer. Set the second block down and tamp it in. Use a level to make sure the wall is even. If it is not even, tamp it until the second block is even with the first block. Continue in this manner until the bottom row of the wall is laid out.

For the second row, use a half block for the first block so that the row will be staggered. Coat the top of the first two blocks with mortar. Begin laying the second row as you laid the first row. Make sure to check that each block is level before moving on to the next block.

Fill the holes with cement. Level off the cement so that it does not interfere with the next layers. Start the third row with a full block, then the fourth row with a half block. Continue in this manner until the retaining wall is the height you need, filling the centers of the blocks every two rows.

Finishing Up

Add a cap row of solid bricks. Paint the finished wall with your choice of color. Back fill along both sides of the wall (the last 2 inches between the footer and the top of the trench).