This video shows us how to build a gravity wall with Allen Blocks. In order to do this, place blocks on top of the base course. You want to make sure that the bottom notch is tight against the front lip of the blocks underneath. Sliding them into place removes any present debris. Running bond is ideal; however, if that is not possible, offset them by a quarter of a block. After making sure the blocks are straight, fill the hollow blocks (and 12 inches behind them) with wall rock. Then smooth over the top and run a plate compactor over it in order to compact the wall rock. Make sure to be safe as well.