How to Build a 1,500-Square-Foot Ready Rock Retaining Wall
- Staff Desk
- 1 hour ago
- 4 min read
Large commercial retaining walls require careful planning, solid base preparation, and precise installation. This blog showcases the process of constructing a 1,500-square-foot big block retaining wall using Ready Rock blocks, built in front of an existing concrete masonry wall that was beginning to fail.
The goal was to create a long-term, stable solution without disturbing nearby residences. Below is a detailed walkthrough of the key steps and techniques used.
Project Overview
The existing CMU (concrete masonry unit) wall behind the new build had started to deteriorate. Because removing it would have disrupted the neighboring property, the owner chose to build a new retaining wall in front of it, sacrificing a small section of the parking lot.
The new structure used large interlocking Ready Rock blocks, providing both mass and strength while maintaining an attractive, uniform appearance suitable for a commercial setting.
Step 1: Preparing the Base
The foundation is the most critical part of any retaining wall. The crew began by grading the area and laying down a thin leveling layer of stone, about one to two inches thick. This layer ensured a relatively flat surface for the next step — placing the geogrid stabilization fabric.
Why the Stabilization Fabric Matters
The geo-fabric helps distribute the load evenly and prevents the base material from mixing with the subsoil. It also adds shear strength, helping the wall resist lateral movement over time.
After installing the fabric, the base was built up using three compacted lifts of crushed stone (also called modified stone). Each lift was compacted thoroughly to achieve a solid, level foundation.
Step 2: Screeding and Setting the First Course
To create a perfectly level surface for the first row of blocks, screed pipes were positioned and leveled both front-to-back and side-to-side. A chip stone layer was placed and screeded across these pipes to create a uniform bedding layer.
This step is crucial — any unevenness in the first course will compound as additional rows are added. Once leveled, the base course of Ready Rock blocks was carefully set in place.
Step 3: Backfilling and Compaction
After the base course was installed, backfilling began behind the blocks using modified stone. The backfill was placed in 4- to 5-inch lifts and compacted by hand. This process was repeated as each new course of blocks was added, ensuring consistent support behind the wall.
As the wall grew higher, the fill transitioned from modified stone to clean ¾-inch drainage stone above the drainpipe level to promote water movement away from the wall.
Step 4: Drainage and Filter Fabric
Proper drainage is key to the longevity of any retaining wall. A drain pipe was installed behind the bottom courses to carry water away from the structure. Then, filter fabric was placed — starting under the drainpipe, running up the back of the wall, and folding over the top of the drainage stone. This fabric prevents soil fines from migrating into the stone backfill, which could clog the drainage system over time.
Even though a concrete wall existed directly behind the new wall, the engineer required the filter fabric to remain in the design. This was a preventive measure in case the old wall eventually failed or eroded, exposing soil to the drainage zone.
Step 5: Structural Adjustments and Finishing Touches
During the build, a few additional components were added for functionality and protection:
Concrete curb: Formed and poured along one end to prevent future impact damage from stored materials or vehicles.
Height modification: The owner requested the wall’s height be extended to match the higher section along its full length. This required removing the previous top course, adding a full interlocking course beneath, and reinstalling the top blocks.
Despite the change, the added height did not compromise structural integrity since the entire wall was built to uniform specifications.
Step 6: Completion and Inspection
Once the top course was in place, crews:
Trimmed and tucked filter fabric,
Installed final drainage stone,
Cleaned up the site, and
Poured an asphalt patch in front of the curb for a smooth transition to the parking area.
The final product was a 1,500-square-foot retaining wall with consistent alignment, clean joints, and long-term durability. Both contractor and owner confirmed that the wall met specifications and performed as intended.
Key Takeaways
Why This Method Works
Using large precast retaining wall blocks like Ready Rock simplifies construction while offering structural reliability. Each block interlocks with the next, creating a gravity wall capable of resisting lateral soil pressure without extensive reinforcement.The combination of drainage management, graded backfill, and geofabric stabilization ensures that the wall can perform under both static and hydrodynamic loads for years.