How to Design a Retaining Wall Project

Uploaded by blockvideos on 31.03.2007

Designing your Allan Block Project
when designing your project, be sure to consider design elements such as, wall height, setback, slopes, and surcharges.
These elements will help you determine whether to build a gravity or reinforced wall.

Walls that rely on their own weight and setback are called Gravity walls.
Under certain conditions, a gravity wall is not enough and additional reinforcement will be needed

these walls are called reinforced walls.
Reinforced walls use geogrid to provide added stability.
AB Reinforcement Grid provides a simple solution for walls up to 6 feet high.

Used together, AB blocks and reinforcement grid create a solid structure
with more resistance to soil pressure
See the guide for Landscape Walls to determine if reinforcement is needed on your project.

The amount your wall leans back into the hill is called "setback".

Allan Blocks come in 6° and 12° setbacks.
12 degree setbacks provide better leverage and require less reinforcement to hold back the pressure behind the wall.

Any weight above a wall is called a surcharge.
Driveways, swimming pools, patios and slopes are common surcharges.
These walls may need additional reinforcement.
For design assistance, contact local engineer.
Slopes can occur above or below a wall.
Slopes above a wall will add more pressure and weight.
Try to maintain a maximum slope of 3:1 above the wall
where you have a ratio of 1 up to 3 back.
A slope below the wall may reduce stability and be prone to erosion.

Contact a local engineer for assistance with this type of wall design

Allan Block offers unlimited design possibilities.
The flexible Allan Block Collections allow you to design with patterns,
flowing curves,
straight walls, stairways and much more
See your local Alan Block Dealer for colors and availability.
The natural feel of a patterned wall adds a beautiful dimension to your landscape
Both the AB Ashlar and AB Europa Collections can be used to create a variety of patterns.

Patterns are typically repeated every two or three courses.
Plan on taking a little extra time to build patterned walls, particularly when building one for the first time.

See the Landscape walls guide for pattern layouts and additional information.
Curved walls are simple to design and easy to build.
The type block or combination of blocks you choose will determine the radius you can create.
See the radius charts in the landscape walls guide for more information.
Terraced walls can be used to create more usable space and build raised gardens

For projects that include terraced walls, the distance between the walls must be
greater than two times the height of the lower wall.
If the distance between the walls is less than this, or for all other terraced applications
contact your local engineer for assistance.
contact your local engineer for assistance
In -wall planters can be used to add color and break up long stretches of wall.
Compaction under the wall sections that curve back into the hill is very important.

Stairs can be easily designed into your project.
The simplest stairs are built using curves, which do not require special skills or cutting of block.

Stairs can be built in front of or into a wall.
Stairs can also be built parallel to a wall.
With imagination and planning, you can design stairs into any wall project.

Choose a style that matches the natural path of your site.
Allan Block's patented raised front lip provides a built-in edge for a variety of materials
to complete your project
when installing stair treads
AB Capstones, pavers and poured concrete are good options.

For finishing your wall, consider using AB Capstones , crushed landscape rock, mulches or planting materials.

Estimating materials is easy when using the AB Estimating Wheel or
the Excel based AB Estimating Tool
These easy to use tools will give you material estimates for block, reinforcement grid, wall rock, backfill materials and AB Capstones

Visit for download information or your local dealer for any assistance in estimating the materials on your project

For the next step in Plan Design Build, go to Building a Wall or
visit us at