Building a retaining wall on a slope requires more than stacking wall units against a hillside. A commercial system must account for soil pressure, groundwater, surface runoff, wall height, nearby structures, and loads from vehicles or equipment. On steep sites, several shorter walls may be used instead of one tall wall. This approach is called terracing. When properly designed, tiered walls can distribute pressure across multiple elevations and create usable areas between wall sections. However, the tiers must be evaluated as one connected earth retention system, not as separate walls.
How Do You Terrace a Commercial Slope?
Understanding how to terrace a slope starts with a survey of the grade, soil, drainage paths, property boundaries, and nearby structures. The design team then divides the elevation change among two or more retaining walls.
A commercial terracing plan typically includes:
- The height and setback of each wall
- The total elevation change
- Drainage behind every tier
- Stable soil or engineered backfill
- Reinforcement where required
- Access for construction and future inspections
- Loads from parking areas, buildings, or equipment
Tiering can reduce the exposed height of each wall and interrupt potential soil movement. It may also create level areas for walkways, seating, or site access. However, adding more tiers does not automatically make a slope stable. Water movement, weak soil, and added loads can still affect the entire system.
Commercial teams should involve a qualified engineer when soil conditions, groundwater, wall loads, or total height create added risk. Colorado sites may contain clay or other soils that change as moisture levels rise and fall. Soil testing helps the engineer select suitable backfill, reinforcement, drainage, and foundation details.
How Far Apart Should Tiered Walls Be?
Tiered retaining wall spacing affects whether the upper wall adds pressure to the lower wall. The Concrete Masonry and Hardscapes Association (CMHA) states that an unreinforced upper wall generally should be set back at least twice the height of the lower wall. For example, a four-foot lower wall would need about eight feet of separation under that general guideline.
That spacing is not a universal design rule. Walls placed closer together may behave like one taller structure and require engineered reinforcement. The design must also consider slope angle, soil strength, wall batter, groundwater, and surcharges. A surcharge is an added load behind the wall, such as a parking lot, building, delivery area, or steep upper slope.
Even when the spacing meets the two-times-height guideline, a professional should evaluate the complete system. Site conditions can require wider setbacks or a reinforced design.
How Tall Can a Retaining Wall Be?
When property teams ask how tall a retaining wall can be, the answer depends on the wall system, soil, reinforcement, nearby loads, and local rules. CMHA guidance notes that unreinforced segmental walls are commonly limited to about three or four feet. Taller walls generally require geogrid or another engineered reinforcement system. Geogrid is a strong mesh installed in compacted soil behind the wall to help resist movement.
Walls over about four feet often require engineered design or permit review, but requirements vary by jurisdiction and project conditions. Walls supporting a surcharge may need engineering at a lower height. In Denver, retaining walls over 12 inches require a zoning permit, and other reviews may apply based on height, location, and project type.
This information is general planning guidance, not legal or engineering advice. Project teams should confirm current requirements with local officials and qualified design professionals.
Do You Need Help With a Retaining Wall in Denver?
A successful retaining wall project in Denver begins with accurate site information and a design suited to the soil, drainage, slope, and commercial use. Designs by Stonescapes works with property managers, developers, and facilities teams to plan durable retaining systems for multifamily, office, retail, and mixed-use properties.
Our team can evaluate access, grading, drainage, wall materials, and connections to the surrounding commercial hardscape. We can also coordinate with engineers and other project professionals when the wall requires reinforced or permitted construction.
Every retaining wall on a slope needs a site-specific plan. Contact us to discuss terracing, repairs, or a new retaining wall for your Denver commercial property.ucture performs reliably under pressure and avoids the common failures caused by unmanaged water.