Stepping Up A Slope: Building Retaining Wall Step-Ups
Walls built on a sloping grade require a stepped-up base to remain stable and level, without burying extra block.
Step 1: Excavating the Trench
- Begin the base course for your retaining wall step-ups at the lowest wall elevation
- Excavate leveling pad a minimum of 32 inches wide, according to Heritage Block’s guidelines. If there is a slope present, contact your local site civil engineer for help.
- Compact sub-grade to at least 95% Standard Proctor and level the base trench, making at least two passes with your plate compactor.
Step 2: Put in Drainage
- Find the lowest possible point towards the back of your trench
- Place a 4-inch socked drain pipe on backside of wall—drain should extend to daylight
Step 3: Start Preparing for the Next Level
- Encase the installed drainage pipe with a minimum of 6 inches washed #57 drainage aggregate
- Check if area is level
- If level, compact the base material with your plate compactor making a minimum of two passes
Step 4: Beginning the Second Level
- Begin by excavating, making sure to accommodate for the base material and buried block
- Compact and level the area
Step 5: Place the Block
- Place the base course of blocks and ensure it is level
- Core fill the blocks and behind the blocks, as well as the base area, for the the next step-up
Important: Make sure the blocks and the base of the next step-up are level.
Step 6: Compact the Rock
- Compact the rock directly behind the already-installed blocks and the next step-up area, making a minimum of two passes with your plate compactor.
Continue these steps until your retaining wall step-ups have been completed. Keep in mind that the next level of the step-up must have a course of block completely buried to maintain the proper base depth and prevent erosion that could cause the wall to fail.