Retaining Wall Types for Utah Soil: Boulder, Block, or Concrete?

Not all retaining walls perform equally on Utah soil. The clay-heavy, freeze-thaw conditions in northern Utah have a way of exposing walls that were built with the wrong system, or built correctly for a different climate. Boulder walls that thrive in the Wasatch foothills may not be the right choice on a West Haven lot with a high water table. Segmental block systems that work well in temperate climates can develop drainage problems in Utah’s wet springs.

Here is an honest comparison of the main retaining wall types and how each performs in northern Utah’s specific soil and climate conditions.

Why Utah Soil Makes Wall Selection Matter More

The valley floor from Ogden through Salt Lake City sits primarily on Lake Bonneville sediment: fine-grained, silty clay that expands when wet and shrinks when dry. This shrink-swell behavior is the main enemy of retaining walls in this region.

Clay soil behind a retaining wall generates significantly more lateral pressure than sandy or gravelly soil. It also retains water, which increases that pressure further. In winter, that saturated soil freezes, expands, and pushes. In spring, it thaws and the cycle repeats.

Any retaining wall system in northern Utah needs to handle this combination: high lateral earth pressure, drainage requirements, and freeze-thaw cycling. How well each system handles these factors varies considerably.

Boulder Walls

Boulder walls — large natural stone or quarried rock placed in courses — are the most traditional retaining wall system in the Wasatch Front area. They have been used here for generations, and when done well, they are among the most durable options for Utah conditions.

How They Perform in Utah Soil

Boulder walls are gravity walls. They hold back soil through their own mass, not through structural reinforcement or engineering geometry. A well-built boulder wall in good rock is massive enough to resist the lateral pressure from clay backfill.

Their biggest advantage in Utah’s climate is drainage. Gaps between boulders allow water to pass through naturally, which prevents hydrostatic pressure from building up behind the wall. This is the main failure mode for poorly drained walls — water accumulates, pressure builds, and the wall moves or tips.

Boulder walls are also naturally tolerant of some differential movement. If the base settles slightly or frost pushes at one section, a dry-stacked boulder wall can flex in ways that a rigid concrete wall cannot.

Best Applications

Boulder walls work best on:

• Sloped bench-area properties in North Ogden, Ogden, and foothill communities
• Properties with access for large equipment to place rock
• Walls with natural aesthetic requirements — boulder walls look at home in the Wasatch landscape
• Rural and Morgan County properties where the natural stone look fits the terrain

Limitations

Boulder walls require larger machinery to place rock effectively. They are not practical in tight urban lots where access is limited. They also have practical height limits — beyond about 6 feet, a proper boulder wall requires significant rock mass and careful engineering of the base courses.

Segmental Block Walls

Segmental retaining wall (SRW) systems — sold under brand names like Versa-Lok, Allan Block, and others — are manufactured concrete blocks designed to interlock in a specific geometry. They are widely used in residential construction because they are relatively fast to install and available in many finishes.

How They Perform in Utah Soil

SRW systems perform well in Utah when drainage is installed correctly. The key phrase is “when drainage is installed correctly.”

Segmental block walls rely on a geogrid reinforcement system (layers of plastic mesh embedded in the backfill) for taller walls, and on proper drainage aggregate (clean gravel) directly behind the blocks to prevent hydrostatic pressure. In Utah’s clay soils, both of these elements are non-negotiable.

A segmental block wall installed without adequate drainage behind it will fail in northern Utah. The clay won’t drain, water builds up, and the wall either tips forward at the base or blows out a panel. We have seen this happen on walls that were only a few years old.

When drainage is done right — clean gravel drainage zone, perforated drain pipe at the base, geotextile separation between native clay and drainage aggregate — SRW systems hold up through Utah winters.

Best Applications

SRW blocks work well for:

• Residential landscaping walls in the 2–5 foot range
• Urban lots with limited access where large rock cannot be delivered
• Projects where a specific finish aesthetic is required
• Tiered wall systems where multiple shorter walls step up a slope

Limitations

SRW systems require the drainage details to be done correctly. They are also vulnerable to poor quality control during installation — if the courses aren’t properly leveled and geogrid isn’t placed at the right intervals, the wall will lean or fail over time. Verify that your contractor has experience with the specific system being installed and understands the drainage requirements.

Poured Concrete Walls

Poured concrete (or concrete block/CMU) retaining walls are engineered structures. They are designed by a structural engineer, formed, reinforced with rebar, and poured. They are not as common in residential landscaping but are used for taller walls, commercial applications, and situations where a vertical face or specific geometry is required.

How They Perform in Utah Soil

Concrete walls are the most structurally capable option for significant retained heights or heavy surcharge loads. A properly engineered concrete wall can handle conditions that would exceed the capacity of a gravity wall or SRW system.

The engineering addresses the clay soil issue directly — the engineer accounts for the lateral earth pressure of clay backfill and the additional hydrostatic pressure, and designs the wall to resist those loads. Drainage is still required (a concrete wall without drainage will develop hydrostatic pressure that can crack or topple it), but the wall’s structural capacity is explicitly designed.

Best Applications

Concrete walls are typically used for:

• Walls over 6 feet of retained height
• Walls with significant surcharge loading (driveways, parking areas, structures above)
• Commercial and government projects
• Applications requiring a clean vertical face

Limitations

Concrete walls cost more than gravity or SRW alternatives. They require engineering drawings and permits in most Utah jurisdictions. They are also aesthetically industrial — some property owners prefer the natural look of boulder or textured block.

Which Should You Choose?

For most northern Utah residential retaining walls in the 2–5 foot range, the choice comes down to:

• Boulder wall if you have access for equipment, a foothills or rural aesthetic, and a budget that supports the material and placement cost
• SRW block if you need a specific finished look, have limited access, or prefer the consistency of an engineered system — with the understanding that drainage details are critical
• Concrete if you are over 5–6 feet of retained height, have a surcharge load, or have a commercial/government application

For Salt Lake City bench communities with sloped lots and significant grade changes, engineered solutions — whether SRW with geogrid or concrete — are more common because the wall heights required to manage the terrain demand more than a simple gravity system.

In Layton, Farmington, Syracuse, and the Davis County flatlands, most residential walls are shorter and SRW systems are common. On the bench in Weber County, boulders fit the terrain and the aesthetic.

Getting the Right System for Your Site

The right retaining wall for your property depends on your specific soil conditions, wall height, access constraints, aesthetic goals, and budget. A site visit is the only way to give you a reliable recommendation.

AccuRite’s retaining wall work covers boulder walls, SRW block, and concrete construction across Weber, Davis, and Salt Lake counties. We can assess your site, recommend the right system, and handle the permitting and installation from start to finish.

Contact AccuRite to talk through your wall project.