What it is
3/4-inch crushed limestone, sometimes called utility rock or "rough rock." A step coarser than our 1" crushed limestone and slightly cheaper per ton. Angular pieces that lock together when compacted.
What it is for
Cheap, structural base material. The hidden layer under most hardscape:
- Driveway base course. Under a finish course of crushed limestone or DG.
- Drainage backfill. Around foundation perimeter drains, behind retaining walls, in French-drain trenches.
- Heavy-equipment access paths. Temporary work areas where you need to stabilize soft soil so a backhoe can operate.
- Fill for low spots in rural driveways. Throw it in, compact, top with finer rock.
How it compares
| Utility Rock 3/4" | 1" Crushed Limestone | |
|---|---|---|
| Cost per ton | Lower | Slightly higher |
| Compaction | Good | Very good |
| Use as base under finer rock | Yes | Yes |
| Use as finish surface | Rough — not recommended | Acceptable for rural driveways |
| Surface walkability | Coarse, hard on bare feet | Coarse, hard on bare feet |
If you're building a finished driveway, lay utility rock as the base (4 inches) and top with 2 inches of 1" crushed limestone. If you're just building a structural pad under a slab, utility rock is sufficient.
How much do I need
For base courses at 4-6" depth:
| Project size | Tons (4" depth) | Tons (6" depth) |
|---|---|---|
| 100 sq ft | 1.3 | 2 |
| 300 sq ft | 4 | 6 |
| 600 sq ft pad | 8 | 12 |
| 1,000 sq ft driveway | 14 | 20 |
Install notes
- Excavate to subgrade.
- Lay woven fabric over the subgrade if soil is soft clay — keeps fines from migrating up.
- Dump and spread utility rock in 2-inch lifts.
- Compact each lift with a plate compactor before adding the next. This is the step DIYers skip — and it's what makes the difference between a base that lasts and one that settles within a year.
- Top with the finish material (limestone, DG, pavers, or flagstone bed).
Buying tips
- Sold loose by the ton — bulk delivery only. A ton fits in a level-loaded pickup; multiple tons need a flatbed or our dump-truck delivery.
- Don't walk barefoot on it — the angular faces are sharp.
- For French-drain trenches under driveways, use utility rock instead of pea gravel — pea gravel can shift under traffic loads.
Contractor notes
Volume pricing at 10+ tons. Tandem-load (20-22 tons) standard. Same-day pickup if you arrive before noon.