View Retaining Wall Backfill Material Background. Backfill refers to the dirt behind the wall. Placed behind the retaining wall to promote drainage of water away from the wall.
When you have built your retaining wall, then you will need to add some backfill to the hole in order to shore up the wall, and prevent any type of collapse of at first, filling the hole manually can seem like a bad idea, particularly if you are not used to working heavy loads.
The most common backfills used to raise the apparent ground level of garden railroads are dirt and gravel. A retaining wall is required if adequate space is not available. Foundation soils at the bottom of the base trench must be firm and solid. The walls constructed for retaining or supporting earth against their back are called retaining walls.