Maximum Wall Heights for a Gravity Retaining Wall Bring your retaining wall and landscape together with a detailed design. Gravity Wall Chart Use the chart below to find the maximum height that your retaining wall can be built before reinforcement is required. Typically most soils will be considered clay. For sand conditions outlined in the table the soil must be a clean, granular material. Learn more on soil types. Maximum Wall Heights - Gravity Retaining Walls Residential Applications Condition Above Landscape Wall Soil Type AB Stones Only of the AB Collection 12° (Ref) AB Collections 6° (Ref) Clay 1.0 m 0.9 m Silty Sand 1.6 m 1.4 m Wall heights listed are for reference only. Clay 0.5 m 0.4 m Silty Sand 1.1 m 0.9 m Wall heights listed are for reference only. Clay 0.8 m 0.7 m Silty Sand 1.4 m 1.2 m Wall heights listed are for reference only. This table 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.