Backfill with Drainage Rock

What happens here

Once the retaining wall blocks are installed, a significant amount of 3/4-inch clear angular rock is used to backfill the trench behind the wall. This material serves as a crucial drainage layer, allowing water to pass through freely and preventing the buildup of hydrostatic pressure against the wall, which is a common cause of retaining wall failure. The video re-emphasizes that only 3/4-inch clear angular rock should be used in the drainage zone, not recycled Class 5 material or pea rock, as these alternatives can clog or shift over time, compromising drainage. The rock is carefully placed to fill the space behind the interlocking blocks.

Goal: 3/4-inch clear angular rock is used to backfill behind the installed retaining wall blocks, creating a robust drainage layer that prevents hydrostatic pressure buildup and ensures the wall's long-term stability.