For many walls, soil backfill will be needed behind the drainage aggregate.

Unreinforced walls often need backfill behind drainage aggregate to reach the new, higher grade at the top of the wall. Reinforced walls need backfill in geogrid-reinforced soil.

Proper placement and compaction of backfill is critical to the stability of your SRW . Poorly compacted backfill puts extra pressure on a wall—especially when it becomes wet.

With drainage aggregate in place, place your backfill soil directly behind the drainage aggregate. Loose lifts of soil should not exceed 6 inches thick when mechanically compacting, or 2 inches when compacting by hand.

Compact the backfill soil, making sure that backfill is not too wet or dry. The amount of effort needed for adequate backfill compaction varies with soil type and moisture content.