To allow for possible adjustments, drive only enough spikes to keep the edging in place. For curves and rounded patio corners, use rigid plastic edging with notches on the outside flange. It may be necessary to anchor each section of edging with spikes to hold curved edging in place. Remove the reference strings. After your subbase material and edging are in place, you will need to lay another inch of road dust on top of the crushed stone.
Road dust is the same material as crushed stone except it is ground much finer.
We lined up a one-inch thick pipe every six feet to serve as depth spacers. Fill road dust in between the pipes. Water the road dust thoroughly and pack it lightly with a hand tamper. Then screen the dust to an even layer by resting a long piece of wood across the spacers. Add extra sand to fill footprints and low areas, then, water, tamp, and screen the sand again until it is smooth an firmly packed.