How Much Road Base for a 40x80 Pole Barn?
How much road base for a 40x80 pole barn: about 88.9 tons for a 6-inch pad covering the 3,200 square foot footprint. Many builders extend the pad a foot or two past the walls, which adds material.
Volume and tonnage calculator →The math
- Area: 3,200.0 sq ft.
- Depth in feet: 6 ÷ 12 = 0.500 ft.
- Cubic yards: 3,200.0 × 0.500 ÷ 27 = 59.26 yd³.
- Tons: × about 1.5 tons per yard = 88.9 tons.
The crushed stone calculator does this for any size.
Related: How Much Gravel for a 40x80 Pole Barn?
Road base needed by depth
| Depth | Cubic yards | Tons of road base | Tons +10% |
|---|---|---|---|
| 4 in | 39.51 | 59.3 | 65.2 |
| 6 in | 59.26 | 88.9 | 97.8 |
| 8 in | 79.01 | 118.5 | 130.4 |
| 12 in | 118.52 | 177.8 | 195.6 |
How deep the barn pad should be
Plan the pad around what the barn will hold. Hay and tools sit fine on 4 inches of compacted stone; tractors, trucks or a later slab pour justify 6 to 8 inches built up in compacted lifts.
Related: How Much Crushed Stone for a 40x80 Pole Barn?
Extending the pad past the walls
Adding 1 foot on every side makes the pad 42x82, or 3,444 sq ft. At 6 inches that is about 95.7 tons. A wider apron sheds water away from the posts and gives the eave drip a place to land.
Layering the base
Strip topsoil, level and compact the subgrade, then spread stone in lifts of about 3 to 4 inches, compacting each. A coarser base topped with a finer, packable stone often makes the most solid floor.
Getting it delivered
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. Road base is a graded stone-and-fines mix built to compact into a load-bearing layer. Ask your supplier for their own tons-per-yard number, since stone source and moisture change it.
Questions people ask
How many tons of road base for a 40x80 pole barn?
About 88.9 tons at 6 inches deep.
How many yards of road base for a 40x80 pad?
About 59.26 cubic yards at 6 inches.
How deep should a pole barn gravel pad be?
About 4 inches for light use and 6 to 8 inches for vehicles or a future slab.
How many tons of road base are in a cubic yard?
Roughly 1.5 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
- Gravel for a Pole Barn Floor: Best Stone, Depth and Tons
- 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 Road Base for a 40x60 Pole Barn?
- How Much Road Base for a 40x64 Pole Barn?
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