Installation Instructions for Retaining Walls

Call 8-1-1 to connect to your local digger's hotline. Ask for someone to come to your property and mark your utility lines before you start digging. In most cities, there is no charge for this service.

Lay a garden hose on the ground. Move the hose to form the desired shape of your retaining wall. Pour sand over the hose and pick the hose up. Follow the indentation left in the sand when digging the retaining wall's base.

Measure the width and height of the stackable blocks or timber being used for the retaining wall. Use a shovel to dig a trench along the sand indentation. Make the trench slightly wider than the timber or block's width and deep enough that the first timber or block is underground.

Use a hand tamper to tamp down the soil in the trench. Lay a level in the trench. Add soil back into the trench as needed to make the trench flat. Tamp down the added soil.

Pour patio paver base into the trench. Spread it 3 inches deep throughout the trench, using a shovel. Lay the level in the trench and maneuver the patio paver base as needed to make the trench straight. Tamp it down with the hand tamper.

Place the first stone or timber into the trench. If the retaining wall forms a circle, start anywhere along the trench. If it forms a line or butts up against another structure, start at one end. If you are using stackable stones, turn the stones used in the first layer upside down. Place a chisel against the flange. Hit the chisel's handle with a hammer to remove the flange and help the block sit flat in the trench.

Place a level on the first stone or timber. If it is not level, remove it from the trench and add sand on the low end. Put the stone or timber back in the trench. Continue laying stones or timber until you reach the end or until a full length stone or timber will not fit.

Measure the distance from the edge of the last stone or timber to the end of the retaining wall. Transfer this measurement to the stone or timber. If you are building with stone, use a piece of chalk and a level to draw a line across the stone where it needs to be cut. Use a masonry saw to cut across the line. Cut timber with a handsaw.

Brush off the first layer's surface with a broom. Cut a stone or timber in half to begin the second layer. This creates an offset. Work across the second row the same way you did the first row. Cut the last stone or timber if necessary.

Spread gravel behind the first two layers of stone or timber and fill dirt behind the gravel. Lay a perforated pipe behind the retaining wall if it is going to be taller than 2 feet. This directs water toward the sides instead of pushing against the retaining wall's front.

Build up the retaining wall until you have reached the final level. Place a tube of construction adhesive in a caulk gun. Cut off the tip with a utility knife. Spread two beads of adhesive on the stone or timber's surface. Lay the final level on top of the adhesive.

Spread a layer of top soil behind the final level of stone or timber.