Maximum Wall Heights - AB Gravity Walls Residential Applications
Condition above retaining wall	Soil Type	AB Stones only of AB Collection 12° (Ref)	AB, AB Metropolitan, AB Aztec & AB Europa Collections 6° (Ref)	AB Fieldstone Short Anchoring Unit (SAU) 6° (Ref)	AB Fieldstone Long Anchoring Unit (LAU) 6° (Ref)
Level	Clay	3 ft. 6 in. 1.0 m	3 ft. 2 in. 0.9 m	3 ft. 7 in. 1.1 m	5 ft. 10 in. 1.8 m
	Silty Sand	5 ft. 4 in.** 1.6 m	4 ft. 7 in. 1.4 m	5.0 ft. 1.5 m	8 ft. 6 in. 2.6 m
Surcharge* 100 psf (4.7 kPa)	Clay	1 ft. 8 in. 0.5 m	1 ft. 4 in. 0.4 m	1 ft. 8 in. 0.5 m	4 ft. 1.2 m
	Silty Sand	3 ft. 10 in. 1.1 m	3 ft. 1 in. 0.9 m	3 ft. 7 in. 1.1 m	7.0 ft. 2.1 m
Slope 3:1	Clay	2 ft. 8 in. 0.8 m	2 ft. 4 in. 0.7 m	2 ft. 8 in. 0.8 m	4 ft. 4 in. 1.3 m
	Silty Sand	4 ft. 8 in. 1.4 m	4 ft. 1 in. 1.2 m	4 ft. 4 in. 1.3 m	7 ft. 4 in. 2.3 m

Table 1 is based on Clay soil having an internal friction angle of 27° (Ref) or better and a Sandy soil having an internal friction angle of 32° (Ref) or better. All heights based on exposed wall heights and include a cap block. The gravity wall heights shown above do not account for seismic loading. Check with a local engineer for assistance if you are in a seismic area. Final designs for construction purposes must be performed by a local registered Professional Engineer, using the actual conditions of the proposed site. *The Surcharge loading category above assumes a solid surface such as concrete, asphalt or pavers having a suitable supporting subgrade.

**Chart Example: A 5 ft. (1.5 m) tall wall in sandy soil with a level surface above can be built with AB Stones of the AB Collection and would typically not require reinforcement, but will require review by a local professional engineer.