How to Build a Small Retaining Wall on the Side of a Pool

Mark the corners and curves of the wall with wooden pegs, and tie a string to connect them in a single line.

Begin at the lower side of the wall, and dig a trench with a square-tipped shovel. It should be as wide as the retaining wall blocks plus 4 inches and as deep as the blocks plus 4 inches so the first course will be buried. Dig until the bottom of the trench is level, and use a tamping tool to compact the dirt.

Pour 2 inches of course-grit sand over the trench to level the first course.

Position the first block on top of the sand against the outer wall of the trench. Put a level on top, and hit the block gently with a mallet until it is level. Set the next block flush against the first. Continue setting the first course, using the level and mallet to make them even.

Begin the second course by setting a block on top of both ends of the first course. Use two half blocks to stagger the joints for increased stability. If you don’t have half blocks, split a whole block with a hammer and chisel. Stretch a line level between the two to make sure they’re level. If they’re not, remove the blocks and adjust the first course until they are.

Set the second course so the lip on the bottom back of each interlocks with the blocks below.

Fill the gap between the first course and the ground with soil, and tamp it down.

Build up the wall one course at a time until it is 3 feet tall or less.

Unroll synthetic landscape fabric, and lay it against the back of the wall until it is a few inches from the top so it won’t be seen. Cut any excess with scissors. This will prevent sediment and moisture from seeping between the joints.

Fill in a 6-inch-wide area behind the back of the wall with gravel to improve drainage. Cover the top of the gravel with river rocks or another decorative stone.