Road base is the most-ordered material we supply — and the most misunderstood. Here's what it actually is and why contractors rely on it.
What Is Crusher Run?
Crusher run — also called road base, dense-grade aggregate, or DGA — is a blend of crushed stone and stone dust produced directly from the crusher without further screening. It contains a full range of particle sizes, from coarse gravel down to fine powder.
That gradation is intentional. The small particles fill the voids between larger ones, creating a dense, interlocked mass that compacts tightly and resists movement under load.
Why It Compacts So Well
The key to crusher run's performance is its particle size distribution. When compacted with a plate compactor or roller, the material achieves very high density — typically 95–98% Proctor density. This makes it stiffer than clean gravel and better suited to carrying heavy loads.
The stone dust component also acts as a natural binder. It holds moisture and can harden over time in dry conditions, further improving stability.
Best Applications
Road base is the standard sub-base material for driveways, parking lots, access roads, and warehouse floors. It's laid beneath asphalt or concrete to provide a stable, level platform that won't sink or heave seasonally.
It's also used as a finished driveway surface in rural and agricultural settings where a hard surface isn't required — it's durable, low-maintenance, and significantly cheaper than paving.
For walkways, shed pads, and RV pads, 4 inches of compacted crusher run is usually sufficient. For heavy vehicle areas, 6–8 inches is recommended.
Installation Tips
Always compact crusher run in lifts — layers no deeper than 4 inches at a time. Trying to compact a 10-inch layer in one pass won't achieve the density you need at the bottom.
Moisture content affects compaction. Slightly damp material compacts better than bone-dry or saturated material. If the ground is very dry, a light watering before compaction improves results.
Allow 24–48 hours after installation before heavy vehicle use. The material continues to settle and lock after compaction, especially in the first few passes of traffic.
