Retaining Wall Installation Instructions

These instructions are intended as a general guide for walls less than 4 feet only. Please consult the technical specification sheet for the wall shape you choose for more specific installation instructions.

Technical information for CypressStone™, Roman Cypress™, and CornerStone® walls over 4 feet requiring engineering and reinforcement are available from a Mutual Materials Representative.

Step 1

Before beginning a retaining wall installation project, you first need to make sure you have the right tools for the job and have selected your retaining wall blocks.

 

 

With the tools and equipment, you are now ready to start building your retaining wall. First mark the area of the wall with chalk or spray paint.

Dig out a trench that is a minimum of 6″ (155 mm) deep plus 1″ for every foot of wall height. Allow 6″–8″ (150–200 mm) of space behind the wall for 3⁄4″ clean crushed rock (this means your trench is a minimum of 12″ or 305 mm wide). Roots and big rocks should be removed from the trench. When the trench is dug out, put 3″ of 5⁄8 minus crushed rock in the trench. Tamp (compact) the base and level it front to back and side to side.

Step 2

Lay the base course of retaining wall blocks. Using a string line at the back of the blocks for alignment, place blocks side by side on the gravel, checking for level in both directions.

TIP: Begin laying block at the lowest point of the wall. It is also easier to start at a straight part of the wall.Complete the base course before proceeding to the second course.

 

 

Step 3

Start placing the second course. Center each block on the seams of the first course.

If using ManorStone®, CottageStone® Advantage, or VineyardStoneTM the connecting lip should be pointed down to overhang the back edge of the base units.

If using RomanStack®, StackStone®, CypressStone™, or Roman Cypress™, the bottom groove should be fitted over the tongue on the base blocks.

If using Celtik Wall®, insert clips as shown on the Celtik Wall® Tech Sheet. This will provide a batter to the wall for better stability. If using CornerStone® the connecting lugs should be pointed down to lock into the cores of the block below them.

To cut blocks for the ends of the wall or in tight curved sections, use a hammer and chisel to score the unit on all sides. Pound the chisel on the score line until the unit splits. Always wear eye protection when splitting blocks. If many cuts are needed, a saw rental may be the way to go.

Step 4

After each course is laid, backfill behind wall with washed 3⁄4″ gravel or drain rock and compact in 3″ to 4″ layers. This step is important to help drainage and to prevent soil from leaching through the wall face.

For an additional safeguard, landscape fabric can also be used between the backfill and the drain rock.

To help drainage behind taller walls, perforated flexible drainpipe should also be used. Slope gravel behind wall so that the pipe laid behind the wall slopes 1″ (25 mm) for every 4′ (1.2 m) toward the desired run-off area.

Step 5

If using RomanStack®, StackStone®, Celtik Wall®, CypressStone™, RomanCypress™ or CornerStone®, place the final layer using cap units for a finished look.

An option for finishing the wall is to secure the top course with construction adhesive. Apply a bead of adhesive with a caulking gun. Lay the top course down on the bead and press firmly.

Finish back filling behind the wall.