Soil Reinforcement Chart
When a Retaining Wall Needs Reinforcement
Reinforced Retaining Wall
Match your wall to the conditions below to find which width and the number of layers of AB Reinforcement Geogrid you will need. To determine the number of rolls needed, multiply the length of your wall (in meters) by the number of layers needed as determined by using the chart below, and then divide by 15.24 m (the length of a roll of AB Reinforcement Geogrid). Typically most soils will be considered clay,for sandy conditions outlined in the table the soil must be a clean, granular material. Not sure what soil type you have?
Soil Reinforcement Chart for Residential Retaining Walls 
Condition Above Wall 
WALL HEIGHT** 
AB Stones of the AB Collection only 
CLAY SOIL 
SANDY SOIL 
No. of Layers 
Width (W) 
No. of Layers 
Width (W) 

0.9 m 
0 
0 
0 
0 
1.2 m 
2 
0.9 m 
0 
0 
1.5 m 
3 
0.9 m 
0 
0 
1.8 m 
4 
1.2 m 
4 
1.2 m 


0.6 m 
1 
0.9 m 
0 
0 
0.9 m 
2 
0.9 m 
0 
0 
1.2 m 
2 
0.9 m 
0 
0 
1.5 m 
3 
0.9 m 
3 
0.9 m 
1.8 m 
4 
1.2 m 
4 
1.2 m 


0.9 m 
2 
0.9 m 
0 
0 
1.2 m 
2 
0.9 m 
0 
0 
1.5 m 
3 
1.2 m 
0 
0 
1.8 m 
4 
1.2 m 
4 
1.2 m 
Condition Above Wall 
WALL HEIGHT** 
AB Collection 
CLAY SOIL 
SANDY SOIL 
No. of Layers 
Width (W) 
No. of Layers 
Width (W) 

0.9 m 
0 
0 
0 
0 
1.2 m 
2 
0.9 m 
0 
0 
1.5 m 
3 
1.2 m 
3 
0.9 m 
1.8 m 
4 
1.2 m 
4 
1.2 m 


0.6 m 
1 
0.9 m 
0 
0 
0.9 m 
2 
0.9 m 
0 
0 
1.2 m 
2 
0.9 m 
2 
0.9 m 
1.5 m 
3 
0.9 m 
3 
0.9 m 
1.8 m 
4 
1.2 m 
4 
1.2 m 


0.9 m 
2 
0.9 m 
0 
0 
1.2 m 
2 
0.9 m 
2 
0.9 m 
1.5 m 
3 
1.2 m 
3 
0.9 m 
1.8 m 
4 
1.2 m 
4 
1.2 m 
** Wall heights are for reference only. 
Example:Using a block from the AB Collection, a 1.5 m high wall built in sandy soil with a level surface above the wall requires three layers of geogrid, 0.9 m wide, but will require review by a local professional engineer.
AB Reinforcement Grid^{™}
Large Roll Grid
AB Reinforcement Grid
AB Reinforcement Grid is biaxial which means it has the same strength in both directions and can be simply rolled out along the wall. It is available in 1.2 m rolls and is 15 m long and is best used for residential retaining walls under 1.8 m tall as outlined in the table above.
Large roll geogrids are strongest along the roll or machine direction and are cut to the design length. They are best suited for retaining walls over 1.8 m high.