Crushed Rock
Also known as: angular rock, crushed stone, compactible rock
Crushed rock is stone that has been mechanically broken into angular, sharp-edged pieces. Those edges interlock when compacted, which makes crushed rock ideal for bases, driveways and pathways that need to stay firm.
In simple terms
Crushed rock is made by running larger stone through a crusher, so the pieces have flat, jagged faces instead of smooth curves. Those jagged faces grip each other and lock in place, unlike smooth round rock that rolls underfoot.
In depth
The defining property is angularity. Angular crushed aggregate has a high "angle of repose" and shear strength, so it resists displacement and compacts to high density — the reason it is specified for structural base and compactible surfaces. It is screened to sizes such as 3/8, 3/4 and 1.5 inch, sold either "clean" (washed, for drainage) or with fines (compactible base). Rounded gravel, by contrast, is smoother and better for decorative ground cover where you don’t walk much.
Why it matters
Choosing angular vs. rounded rock determines whether a surface stays put or shifts: crushed rock for anything load-bearing or walked-on, rounded rock for decorative beds.
Common mistakes
- Using smooth rounded gravel on a pathway, where it rolls and won’t compact.
- Buying compactible crushed rock (with fines) when clean drainage rock was needed.
Examples & uses
- Compactible pathway and driveway surfaces.
- Structural base under pavers (with fines).
- Walk-on areas where rounded gravel would shift.