Retaining walls must be reinforced in order to be effective. Too many forces are at work against a retaining wall that could cause it to tumble over if it is not reinforced correctly. However, reinforcing steps for a retaining wall are simple to implement, and in the end, these reinforcements will save you time and money. The average do-it-yourselfer can insert reinforcement materials into the retaining wall design by following a few tried-and-true methods.
Install vertical rebar into the concrete wall footer. The rebar must be placed into the wet footer and spaced no more than 4 feet apart. Placing the rebar in the centre of the thickness of the footer will ensure proper wall alignment. Use 1/2-inch to 5/8-inch rebar -- the bigger the rebar, the better support it will provide for the wall. The rebar does not need to be attached to anything within the footer. It is inserted into the wet concrete to provide a connection between the retaining wall and the footer, which is responsible for holding the wall vertical.
After the concrete footer dries, install 8- to 12-inch concrete block for the retaining wall. The blocks should run along the path of the rebar. If the rebar is off-centre -- which would prevent the wall from being installed straight -- you may bend the rebar slightly to accommodate the blocks. Place the blocks down over the rebar and onto the wall mortar, assembling the wall row by row to the desired height. You will end up with empty block cells through which the rebar extends. Allow the mortar to dry for 24 hours before proceeding.
Fill the empty block cells that have rebar through them with concrete grout. This should be about every 4 feet. Once the blocks dry, your wall will remain stable and well-attached to the footer by way of the rebar.