Allan Block System
Plan/Design

Residential Installation Manual for Allan Block Retaining Walls
Allan Block is a leading provider of patented retaining wall systems. For over thirty five years Allan Block has been bringing innovative products to the landscape community.
   

Allan Block Retaining Wall Products and Collections
A Complete Family of Wall Products
The Allan Block Collections give you a choice of styles to meet your site and design requirements.
   

AB Collection - Retaining Wall
The AB Collection is our most popular retaining wall collection.
Whether you are building a simple raised garden or tackling a major hillside, the AB Collection will provide just what you need.
Chart showing multiple sizes, and shapes.
Photos of projects using our AB Collection.
   

AB Aztec - Retaining Wall
AB Aztec Collection brings ancient sophistication to modern retaining walls.
Whether you are building a simple raised garden or tackling a major hillside, the AB Collection will provide just what you need.
Chart showing multiple sizes, and shapes.
Photos of projects using our AB Aztec Collection.
   

AB Metropolitan - Retaining Wall
With minimalistic aesthetics and smooth clean lines, the AB Metropolitan line of blocks main focus is on functionality
This style offers a solution for a variety of wall applications, ranging from small residential to large-scale commercial projects.
Chart showing multiple sizes, and shapes.
Photos of projects using our AB Metropolitan Collection.
   

AB Europa - Retaining Wall
The AB Europa Collection offers the look and feel of weathered stone to the landscape.
The hand laid stone effect brings European old world charm and distinction to any retaining wall project.
Chart showing multiple sizes, and shapes.
Photos of projects using our AB Europa Collection.
   

AB Fieldstone - Retaining Wall
AB Fieldstone is our Green retaining wall product. This two-piece system has a facing unit and an anchoring unit.
Allan Block has opened the door to many benefits that are not only Green, but Natural and Friendly as well.
Chart showing multiple sizes, and shapes.
Photos of projects using our AB Fieldstone Collection.
   

AB Reinforcement Grid
Build a Lasting Structure with the Allan Block Advanced Soil Reinforcement Grid
   

Plan for Potential
Lot Lines
Utilities
Permits
Neighbors
Planning the Wall   Allan Block Video Logo
   

Soils
Clay Soils
Sandy Soils
Organic Soils
   

What Affects Wall Design?
Vegetation and the Environment
Determining Wall Height
Cut and Fill
   

Designing a Retaining Wall
Gravity Walls
Reinforced Walls
Maximum Gravity Wall Height Chart
Designing the Retaining Wall   Allan Block Video Logo
   

Conditions Above and Behind the Wall.
Slopes
Surcharges
Setback
   

Under certain conditions, the block weight and setback alone do not provide enough structural support.
Allan Block Reinforcement Grid provides a simple solution by creating a solid structure with more resistance to soil pressure and surcharges.
   

Curves & Serpentines
Whether you chose soft curved walls or classic straight walls, Allan Block has the system to satisfy every design.
Curves accent any landscape, are simple to design and easy to build. Consider how tight or gentle you want the curves to be and choose the block or combination of blocks that are best suited for your design.
   

Corners & Angles
Outside Corners
Inside Corners
Angles vs. Curves
Helpful Hints
   

Enhance Your Retaining Wall With Patterned Designs
Give your landscape a dramatic effect with the AB Ashlar, AB Aztec or AB Abbey Blend patterned walls from the Allan Block Collections
Add a whole new dimension to your landscape! Blend the different sized blocks together into your wall and capture the look of hand laid stone.
   

Designing Stair Options
Stair Design
Stair Building Basics
   

Create Lasting Value
In-Wall Planters and Terracing
Planters
Plantable Walls
   

Water Management
Design for Water
Grading
Ground Water
Concentrated Water Sources
   

Drain Pipes
When Do I Need Drain Pipes?
Typical Drain
   

Getting Ready
Job Site Considerations
Site Access
Wall Rock
Tools & Equipment you may need.
   

Soils
Working with Soils
Soils
Soil Selection
Compaction
   
Building with Allan Block

Basic Installation
Base Preparation
Base Material
Install Base Course
Backfilling and Compaction
Installing a Gravity Retaining Wall from the Base   Allan Block Video Logo
   

Geogrid Installation
What is Geogrid?
How Grid Works
Install Reinforcement
Build an AB Reinforced Retaining Wall with Geogrid Reinforcement   Allan Block Video Logo
   

Stepping up the Base
Building Step-Ups into the Slope
Stepping up a Slope with a Retaining Wall   Allan Block Video Logo
   

Modifying Blocks and Caps
Inside Corners
Outside Corners for Different Setbacks
Cutting Caps - For Corners
Altering Blocks for Curves Walls
   

Building Patterns
Instructions for building patterned walls.
Build a patterned retaining wall   Allan Block Video Logo
   

Retaining Wall Patterns
All of the Allan Block Collections can be used to create a variety of pre-set and random patterned retaining walls.
   

Tips for Retaining Wall Patterns
Patterned walls resemble hand-laid stone walls and will require a certain level of detail and craftsmanship to construct.
   
Building with Allan Block Fieldstone

Building an AB Fieldstone Retaining Wall
Installation details for building a retaining wall using the AB Fieldstone Collection.
   

Fieldstone Step Up
Installation details to show how to step up a slope with a retaining wall.
   

Building Curves with AB Fieldstone
Inside and Outside Curves with AB Fieldstone
   

Corners with the AB Fieldstone Collection
Inside Corners with AB Fieldstone
Outside Corners with AB Fieldstone
   

Step Downs with AB Fieldstone
Creating a step down is similar to building an outside corner as it uses the same facing units that are manufactured with a textured side and has the same placement of the anchoring units.
Modifying Anchoring Units for AB Fieldstone
   
Construction Details

Building Curves in a Retaining Wall
Curves & Serpentines
Building Curves
Inside Curves and Outside Curves
Determining the Radius
How to Build Curved Retaining Walls   Allan Block Video Logo
   

Retaining Wall Curves Using Geogrid Reinforcement
Working with Curves and Geogrid
Inside Curves and Geogrid
Outside Curves and Geogrid
How to Build Curved Retaining Walls   Allan Block Video Logo
   

Building Corners in a Retaining Wall
Corners & Angles vs. Curves
Inside Corners
Outside Corners
How to Build Corners in a Retaining Wall   Allan Block Video Logo
   

Retaining Wall Corners Using Geogrid Reinforcement
Installing Geogrid on Inside 90° Corners
Installing Geogrid on Outside 90° Corners
Installing Geogrid on Outside 90° Corners
How to Build Corners in a Retaining Wall   Allan Block Video Logo
   

Retaining Walls with Stairs
Variety of options for adding stairs into your retaining wall
Ideas for Designing Stairways or Steps in a Retaining wall   Allan Block Video Logo
   

Stairway Installation
Stairway Installation within a Retaining Wall
Excavate the Base Trench and Stair Location
Install the Base Course
Install First Riser
Ideas for Designing Stairways or Steps in a Retaining wall   Allan Block Video Logo
   

In-Wall Planters and Terracing
In-Wall Planters and Terracing
   

Water Features
Water Brings the Landscape to Life
   

Retaining Wall Lighting
Lighting Adds a Dramatic Effect to Allan Block Walls
   

Steps Downs
Stepping Down Your Retaining Wall
Retaining Wall Turn-ins
   

Finishing Options
Finishing Your Retaining Wall
Capping Retaining Walls
Variety of Finishing Options for a Retaining Wall with Allan Block    Allan Block Video Logo
   

Parapets and Post
Parapets or Double Sided Walls
Posts
   
Construction Checklist

Retaining Wall Construction & Inspection Checklist
Compliance of site to latest site plan
Review of reported soil conditions with on-site soils engineer
Review of above-grade water management with project civil engineer
Review of below grade water management with retaining wall design engineer and general contractor
   
Charts and Tables

Estimating Retaining Wall
Estimating the Number of Blocks Needed
   

Maximum Gravity Wall Heights Chart
Find the maximum height that the wall can be built before reinforcement required
   

Soil Reinforcement Chart
Match the wall conditions to find what Geogrid is needed for the wall
   

Radius Chart for Base Course
Determine the appropriate base course radius to achieve the desired wall height at the final top course
   

Patterned Wall Block Quantites Needed per Section
See the amount of blocks per needed pattern section per collection
   
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Water Management

Where does the water go?

Design for Water

The design and performance of most retaining walls are based on keeping the area behind the wall relatively dry. To ensure a quality project, the soils used must not become saturated during construction and the final design must route water away from the back of the wall. Incorporating berms and swales into the final design is an easy way to direct surface water away.

Berm

Berm

Swale

Site layout for water direction

During the design process, develop a thorough understanding of the site and determine where water will come from and how it will be properly managed.

During the building process, stage your materials so surface runoff is not directed improperly. It is also a good practice to cover the infill soils and the entire wall project at the end of each day to prevent water saturation if rain is in the forecast.

Any reinforced wall or walls over 4 ft. (1.2 m) in height or with slopes or other surcharges above the wall will need a toe drain. In all cases wall rock is located within the cores of the block and a minimum of 12 in. (300 mm) behind the block. The toe drain and the wall rock is designed to remove incidental water from behind the wall and is not meant as primary drainage path for above or below grade water management.

Grading

During wall layout it is important to evaluate the entire site to determine if water will drain into the area where the wall will be constructed. Temporary grading may be needed to ensure water will not drain towards the construction area.

Ground Water

Ground water can be defined as water that occurs within the soil. Sources include surface infiltration, water table fluctuation and layers of permeable soils. Ground water movement must be prevented from coming in contact with the wall structure, including the soils behind the wall.

If subsurface or ground water is encountered during construction, consult an engineer to ensure that the water has been accounted for in your design.

Drains must be vented to daylight or connected to a storm sewer system and must be protected from migration of fine material.

Typical retaining wall drain detail
Concentrated Water Sources

Prior to constructing the wall, review drainage plans and details to identify all potential sources of concentrated water. Examples that must be accounted for are:

  • Driveways
  • Slopes above walls
  • Grading of site
  • Water lines, mains or fire hydrants
  • Roof down spouts
  • Sump pump outlets
  • Irrigation systems
Water Sprinkler