Retaining walls are common features in landscaped yards because they can prevent erosion, aid in drainage, increase visual interest and allow for terraced yard designs. In many cases, retaining wall steps must be installed to complement a retaining wall. The specific type of retaining wall will determine the type of staircase to be installed, as step installation is a modified version of wall construction technique. In all cases, ensure durability and safety by careful planning and installation.
Most retaining walls are constructed using concrete bricks or natural stone. These materials can be used to create retaining wall steps, as well. Concrete bricks, because of their regular sizing, are easy to install safely, and many companies even produce special stair bricks. Natural stone is generally a less regular material, although some varieties are quarried in nearly uniform sizes, suitable for stair construction.
The first step in installing retaining wall steps is planning and measuring. The desired height of the staircase should be measured, as should the depth to which it will be recessed into the wall. These measurements are then divided into steps. Each step should be close to 7 inches (about 18 cm) high, and ten inches (26 cm) deep. Steps should be installed with a uniform rate of rise and have the same dimensions, to reduce the risk of tripping.
The site for retaining wall steps should be prepared by digging it out several inches below the eventual level of the steps. If located in the middle of a retaining wall, both sides of the stairway should be treated simply as retaining wall segments of their own, and constructed by stacking and layering blocks or stones. If located at the end of a wall, only one side need be constructed in this fashion. The stairs themselves should be installed using a modified version of the same techniques as the bricks in the wall.
The bottom row of retaining wall steps should be placed on a bed of compacted gravel topped with packed sand, and flush with the level of the earth. A second row, which may be built up out of several bricks, if thick, flat bricks or stones are used, is placed behind the first, also on a bed of packed sand and gravel, but one stair height above the first. Gravel is then used to fill in behind the second row, to create a level surface for a third row, and so forth. The base of each step should be below the level of the top of the step beneath it. Some steps will need to be mortared in place, and some will require the use of a concrete adhesive similar to caulking.
