DIY Cinderblock Walls

Dig out a trench for your foot with the shovel. The footer should be at least 4 inches thick (deep), and its width should be at least half the height of the wall. For example, if your wall is 4 feet tall, your footer should be at least 2 feet wide.

Mix up some mortar in the wheelbarrow, and fill the trench. Flatten the mortar with the flat trowel, wait an hour, and then score the surface with the tip of the trowel to roughen it. Wait 24 hours.

Mix up some more mortar in the wheelbarrow. Shovel at least an inch of mortar on top of the footer you poured the day before. Lay down a row of cinderblocks on top of the mortar layer. Spaced them out roughly a half-inch from each other. Fill the void between the blocks with the mason trowel and more mortar.

Tap the blocks together slightly with the rubber mallet; this ensures that they are compressed slightly and bonded with the mortar. Set the level on top of the blocks, and work your way down the row, tapping the blocks down into the mortar at least a quarter of an inch. Level the first row.

Apply mortar on top of the first row with the mason trowel, and repeat the process in Steps 3 and 4 to add layers to your cinderblock wall.

Check the wall for plumb after you have installed a few rows. Tap the blocks as needed to adjust them for plumb. Make any necessary cuts by marking the pieces with a pencil and tape measure and cutting them down to size with an angle grinder. Wait an hour, then scrape the excess mortar away from the blocks with the mason trowel.