• Tools Needed
  • Rental Equipment
  • Installation Instructions
    • Step 1: Planning & Layout
    • Step 2: Excavation
    • Step 3: Leveling Pad
    • Step 4: Base Course
    • Step 5: The Next Course
    • Step 6: Drainage Design
    • Step 7: Compaction
    •  ​Step 8: Capping
    •  ​Step 9: Finish Grade & Surface
    •  Step 10: Site Cleaning & Restoration

Tools Needed

  • Shovel
  • Measuring Tape
  • Rake
  • Hammer (2lb)
  • Tamper
  • Chisel (4”)
  • Line Level
  • Mason String
  • 4 ft Level
  • Torpedo Level
  • 3/4” PVC (1” O.D.)
  • 2x6 (straight for screeding)
  • Broom
  • Gloves
  • Safety Goggles

Rental Equipment

A 3hp to 5hp vibratory plate compactor (not a jumping jack) should be used. Although you can achieve compaction without this equipment, it is recommended, as the quality of your base is highly dependent on compaction.

If you are planning a project where cuts will be necessary, you may also want to rent a concrete saw. Check your Yellow Pages under rental for current rental rates and availability.

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Installation Instructions

1. Planning & Layout

Map out where you want the wall to be installed or have a surveyor stake out the wall’s placement. Figure out the length and height of your wall. A Romanstone Hardscapes Dealer will help calculate the amount of materials and estimate the cost of your project. Call local utilities and cable to mark locations.

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2. Excavation

NOTE: Before any digging call your local utility companies to locate any underground lines.

Excavate for the leveling pad to the lines and grades shown on the approved plans. The trench for the leveling pad should be at least twice as wide as your block and deep enough to bury the first course below grade, plus 6 inches for the leveling pad. Ensure that a minimum of 4 inches or 10 percent of the total wall height (whichever is greater) is below grade.

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3. Leveling Pad

An aggregate leveling pad is made of compactible base material of ¾ inch minus with fines. If the planned grade along the wall front will change elevation, the leveling pad may be stepped up by the height of the block to match the grade change. Always start at the lowest level and work upward. Compact the aggregate, making sure it’s level front to back and side to side.

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4. Base Course

This is the most important step in the installation process. Begin laying block at the lowest elevation of the wall. Chisel off any lip on the rear of the block so that the block will lie flat on the leveling pad. Place first block and level, front to back and side to side; lay subsequent blocks in same manner. Place the blocks side by side, flush against each other, and make sure the blocks are in full contact with the leveling pad. Level front to back and side to side. Masons line will help keep your courses straight and level. Place soil in front of the base course and compact. Base course should be buried. Continue to fill and compact after each course is laid. If the wall is on an incline, don’t slope the blocks. Step them up so they remain consistently level.

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5. The Next Course

Fill cores and voids between blocks with ¾ inch clean drainage aggregate prior to laying the next course of block. Clean any debris off the top of the blocks. Place the second course of blocks on top of the base course. Pull each block forward as far as possible to ensure the correct setback. Maintain a running bond. Cut partial units to stay on bond. A circular saw with a masonry blade is recommended for cutting partial units. Backfill with drainage aggregate directly behind the block, adding 6 to 8 inches at a time. Add soil fill behind the aggregate. Compact before the next course.

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6. Drainage Design

Each project is unique. The grades on the site will determine at what level to install the drainpipe. Place the drainpipe (4-inch perforated piping) so water drains down and away from the wall into a storm drain, or daylight just above grade. Fill in the area behind the blocks with clean drainage aggregate, at least 1 foot from the wall.

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7. Compaction

Shovel the backfill soil behind the drainage aggregate and compact the backfill with a hand operated compactor. Make sure the aggregate is level with or slightly below the top of the base course. Continue to fill and compact after each course is laid.

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8. Capping

Start capping from the lowest elevation. If the wall elevation changes, stack caps where the wall steps up. Lay caps at the elevation change and work back toward the previous step up. Cut caps with a diamond- blade saw to fit, as needed. Carefully glue with a high-strength concrete adhesive.

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9. Finish Grade & Surface

Protect the wall with a finished grade at the top and bottom. To ensure proper water drainage away from the wall, use 6 inches of soil with low permeability and seed or plant to stabilize the surface. Consult the wall design engineer if water may be directed behind the wall. If needed, create a swale to divert water away from the wall. This will minimize water seeping into the soil and drainage aggregate behind the wall.

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10. Site Cleaning & Restoration

Brush off the wall and pick up any debris left from the construction process. Planting vegetation in front and on top of the wall will help reduce the chance of erosion.

Congratulations! You have now installed a maintenance free retaining wall. You can enjoy it for a long time to come.

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