Do-It-Yourself Concrete Block

Dig out an area for your footer, which is the foundation for the wall, with a shovel. It needs to be at least 4 inches deep and as wide as half the height of your wall, so if you have a 4-foot wall you need to have a 2-foot wide footer centered under the wall. Mix up some concrete in the wheelbarrow with the shovel and pour it into the trench. Let it dry for 24 hours.

Mix up some more concrete mix in your wheelbarrow. Shovel a layer about 1 inch thick on top of your footer to serve as the base for the block wall. Layer a row of blocks across the top of the footer with around 1/2 inch of spacing in between them. Use the mason trowel to fill the gaps between the blocks with mortar.

Tap the blocks together lightly with the rubber mallet so they bond with the concrete. Place the level across the top of the first row of blocks and tamp them down slightly into the bed of mortar, using the level to guide your tamping so the first row is completely level across the entire row. Use the masonry trowel to apply an inch of mortar on top of the first row.

Set the second row on top of the first row, alternating the second row so the blocks are centered on top of the vertical joints of the first row. This means if you have a full block at the end of the first row, you can start with a half block on the second row. Fill the gaps between the blocks and tamp them into place with the level and mallet.

Match the third row to the first row, and the fourth to the second, and so on and so forth as you go up the wall. Keep each row level, and check the wall every couple of rows with the level to ensure the wall is plumb. After the mortar has started to set up, scrape it off the face with the mason trowel to leave behind filled, smooth joints. For walls over 4 feet in height, consult with an engineer about placement of rebar or other supports.