Crusher run is the common name for dense graded aggregate or DGA, a grade of stone generally used as a base under asphalt, roads, and concrete or interlocking walls. The word aggregate is a general term for crushed stone used with a binding medium to form compound materials.
Aggregates are often the by-products of other industrial activity, and crusher run is simply the small particles left over from stone crushing which “run” out of the crusher. The binding material in this case is composed of small dust particles that fill the spaces between the larger pieces, forming a hard-packed mix. Traffic will make this mix become more compact until it is, in effect, a solid stone mass. It is quite durable and will resist erosion except in cases of catastrophic flooding.
Because of this compacting, crusher run provides a firmer base than ordinary soil. For instance, concrete or asphalt that is laid down on typical soil may look firm immediately after application, but after years of traffic it will begin to sag in places because the dirt underneath is not firm and settles unevenly. That is how potholes happen.
If you are the unhappy property owner, sagging asphalt and concrete can result in damage that is inconvenient, unsightly and very expensive to repair. If you’re trying to sell the property, cracked asphalt and concrete can seriously decrease its value.
Once this sagging has started, it probably will continue. Cracks will spread, potholes will get bigger and the cost of repair will get higher.
Luckily, this is one of those problems that is much cheaper and easier to prevent than it is to fix. The simple solution is to prepare the surface first. If a layer of crusher run is laid down as a base for the concrete, it will compact into a rock-hard substance that will be firm and not sag over time. Potholes will not occur and there will be less chance of cracking. The surface will retain its integrity for many years, and the increase to the value of the property will more than pay for the initial cost.