What is Crusher Run?

What is Crusher Run and Why is It Used?

(Also Called: Crush and Run)

Crusher run is a blended mix of coarse aggregate and fine aggregate. The combination of both crushed stone and stone dust creates a low void content (the amount of space or air between the pieces of rock in a mix) that is valuable in concrete construction for its compaction ability and drainage characteristics. Crusher run is typically used underneath concrete slabs, patios, driveways, sidewalks, and walkways and ranges in sizes from ½” to 4” with stone dust.

base concrete slab fig TriStar Concrete

How Much Crusher Run Do You Need?

Crusher run is ordered by the ton. Since crusher run weights approximately 2,500 lb. per cubic yard, first determine the volume requirement of your project. Do this in the following steps:

  1. Calculate the square footage of your project (L’ x W’)
  2. Multiply this by the depth of crusher run desired in feet (D’) e.g. 4” of crusher run would equate to 0.33’
  3. Divide by 27 to convert cubic feet to cubic yards
  4. Multiply by 2500 to determine the total weight in pounds
  5. Divide by 2000 to determine the tonnage required

Ultimately, the equation looks like this:

crusher run formula fig TriStar Concrete

How is Crusher Run Delivered?

The quarry supplying the crusher run will either have their own dump trucks for delivery or they will contract out dump truck delivery. Homeowners or contractors can pick-up crusher run themselves to save delivery costs, but they must have a dump truck or dump trailer to safely haul the material.


How is Crusher Run Laid Out & Compacted?

Once the subgrade has been cut, compacted, and formed, the crusher run is spread out with a bobcat or skidsteer. After four inches of crusher run is laid out, both the skidsteer and a jumping jack are used to compact the crusher run to create a firm sub-base for the concrete to be poured.