Crusher Run

Crusher run comes straight off the crushing process at a quarry, where limestone, granite, or trap rock is fed through crushers and screened, but not washed. That is the key difference from clean, washed stone. Instead of separating out a single particle size, crusher run keeps the full range, from the top stone size down to fine dust, all mixed together. That gradation is why it is labeled things like 3/4-inch minus or 2-inch minus, meaning everything at or below that size is present. Regional names for the same basic product include 411 and 421 in parts of the Northeast, ABC (aggregate base course) in the Carolinas and Southeast, QP (quarry process) in the Northeast, and dense grade or dense graded aggregate elsewhere. The exact top size and parent rock vary by quarry, so two suppliers' crusher run can look and perform differently even under the same name. Always confirm gradation before ordering if a project has tight tolerances.

Start by excavating to the total depth needed, typically 6 in. for a driveway or 3 to 4 in. for a walkway or patio, plus room for any topping material. Spread crusher run in lifts of no more than 2 to 4 in. and compact each lift with a plate compactor or roller before adding the next. Compacting too thick a layer at once leaves the bottom loose, which shows up later as settling or rutting. Expect the material to lose 10 to 20 percent of its loose volume as it compacts, so order extra rather than the bare minimum. Crush the surface to a slight crown or slope so water runs off rather than pooling, since compacted crusher run does not let water pass through it. Check grade with a screed board or laser level before setting pavers, slabs, or a finish surface on top.

Compared with clean or washed gravel (#57, #8 stone). Clean gravel is screened to one size range with open voids that drain freely but never lock together, so it stays loose and shifts underfoot. Crusher run keeps the dust and fines that fill those voids, giving it the interlock and compaction strength that washed stone cannot match for a driveway or base.

Compared with stone dust or screenings alone. Stone dust is just the fine byproduct, useful for a smooth paver setting bed or finishing layer. Crusher run keeps the coarser stone fragments mixed in with that dust, giving it real structural strength and a rougher surface, rather than the fine, sand-like texture of pure screenings.

How much crusher run do I need. Use a crusher run calculator or do it by hand: multiply length by width by depth in feet, divide by 27 for cubic yards, then multiply by about 1.35 tons per cubic yard, keeping in mind suppliers range from 1.25 to 1.5 tons/cy. A cubic yard covers about 324 sq ft at 1 in. deep, down to 81 sq ft at 4 in. Add 10 to 15 percent extra to cover compaction loss so you are not short mid-project.

How crusher run is sold and delivered. Crusher run is sold in bulk by the cubic yard or by the ton, delivered loose by dump truck for larger projects or by the scoop for smaller ones. Because gradation and parent rock vary between quarries, confirm the top size and material source when ordering so color and compaction behavior match your expectations across the whole job, especially if you are patching or extending an existing surface.