How Much Crusher Run for an 18x20 Carport?
An 18 by 20 foot carport (double) covers 360 square feet. How much crusher run for an 18x20 carport: plan on 10.3 tons for a 6-inch pad that will carry vehicles.
Volume and tonnage calculator →The math
- Area: 360.0 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic yards: 360.0 × 0.333 ÷ 27 = 4.44 yd³.
- Tons: × about 1.55 tons per yard = 6.9 tons.
The crushed stone calculator does this for any size.
Related: How Much Crusher Run for a 18x20 Parking Pad?
Crusher run needed by depth
| Depth | Cubic yards | Tons of crusher run | Tons +10% |
|---|---|---|---|
| 4 in | 4.44 | 6.9 | 7.6 |
| 6 in | 6.67 | 10.3 | 11.4 |
| 8 in | 8.89 | 13.8 | 15.2 |
Building the carport base
Most steel carports can anchor into a compacted gravel pad with auger or rebar anchors. Make the pad slightly larger than the frame and keep it level so the frame goes up square.
Related: How Much Gravel for a 18x20 Parking Pad?
Depth for vehicles
Four inches works on firm ground for cars. Six inches is safer for trucks, heavy SUVs or soft soil.
Ordering and delivery
Small dump trucks commonly carry around 5 to 10 tons and tri-axles more, but loads vary by truck and state, so ask the yard what fits in one trip. Crusher run mixes stone and stone dust, so it packs nearly solid when compacted in layers. Round up by about 10 percent for compaction and uneven ground.
Tools for the job
For anything bigger than a small path, rent a plate compactor; hand tampers cannot match it. A wheelbarrow, shovels, a hard rake and stakes with string are the rest of the kit. Wet the stone lightly before compacting so it binds.
Common mistakes
The most frequent problem is ordering for the finished depth without allowing for compaction, which can shrink a loose layer by 10 to 20 percent. Another is skipping fabric on soft soil and watching the stone vanish into the mud over the first wet season. Spreading everything in one thick layer instead of compacted lifts also leaves a soft, rutted surface.
Questions people ask
How many tons of crusher run for an 18x20 carport?
About 6.9 tons at 4 inches or 10.3 at 6 inches.
Can a carport sit on gravel?
Many metal carports anchor into compacted gravel with ground anchors; check your kit.
How many tons of crusher run are in a cubic yard?
Roughly 1.55 tons for planning, but suppliers vary with stone size and moisture.
Should I put landscape fabric under the stone?
On soft or clay soil, a woven geotextile keeps stone from sinking into the dirt and makes the layer last longer.
Related guides
- How Much Does a Ton of Gravel Cover? Depth Chart
- Tons to Cubic Yards for Gravel: Conversion Chart
- Crushed Stone vs Gravel: Differences and Best Uses
- Geotextile Fabric for Driveways: Woven vs Nonwoven and How Much You Need
- Compacting a Driveway Gravel Base in Lifts
- How Much Gravel for an 18x20 Carport?
- How Much Crushed Stone for an 18x20 Carport?
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