Start with your shed maker’s foundation requirements, then choose the exact crushed-stone product and pad design. Site Prep recommends 3/4-inch clean stone for its prefab-shed foundations, while other suppliers describe fines-bearing road-base systems.1, 3 Those are different approaches, not interchangeable product names. Shed floor construction, soil, drainage, loads and local requirements determine whether a gravel pad is appropriate.
Clean crushed stone or a fines-bearing mix?
| Source | What the current page says | Limit |
|---|---|---|
| Site Prep, foundation installer | Uses 3/4-inch clean stone, power compaction and construction-grade separation fabric. | Its system for prefab sheds; not approval for every shed or soil. |
| Landscape Barn, stone supplier | Recommends clean 3/4-inch crushed stone; describes stone dust as a possible leveling layer. | Supplier guidance, not a universal requirement for stone dust. |
| Hello Gravel, supplier | Describes road base and sand, but also describes pea-gravel layers elsewhere. | Page has conflicting materials and layer depths; not used as a complete installation recipe. |
| Sheds by Fisher, shed builder | One section says avoid washed/clean stone; another recommends clean/washed stone and also says use crusher run. | Internal contradiction remains unresolved; not a decisive specification. |
Sources: Site Prep, Landscape Barn, Hello Gravel and Sheds by Fisher.1, 2, 3, 4 Do not resolve these differences by mixing all their layers together. Obtain the exact foundation instructions from your shed maker or qualified installer before ordering. A size label alone does not establish fines content, density or suitability.
Why the shed itself matters
Site Prep distinguishes prefab sheds with built-in wooden floors from garages or sheds without built-in floors: it favors stone pads for the former and concrete for the latter. It also notes that local requirements can call for added concrete piers.1 This is installer guidance, not a national building-code rule. Confirm permitted foundation type, anchoring, footing/frost requirements and delivery access for the actual building.
Depth, footprint and fabric are design choices
Site Prep gives a general 4–6-inch depth range and says a foundation should be at least 4 inches deep and extend 12 inches beyond each side. Landscape Barn describes 4–6 inches of compacted stone for most residential sheds and up to 8 inches for heavier structures.1, 2 These are source-specific starting points, not a load calculation or guarantee for a large, heavy or sloped installation.
Site Prep says woven fabric is standard in its gravel-pad system for separating stone from soil. Landscape Barn likewise discusses heavy-duty fabric beneath the stone.1, 2 The old claim that the sources did not discuss fabric was incorrect. That does not make one generic “weed barrier” suitable for every soil or pad. Confirm the specified separation material and construction details.
Calculate volume without hiding its basis
Pad length = shed length + twice the chosen side extension.
Pad width = shed width + twice the chosen side extension.
Cubic yards = pad length (ft) × pad width (ft) × depth (in) ÷ 324. This is the geometric volume at the stated depth. If it is a finished compacted target, a loose delivered order needs a defined conversion. If the depth varies, calculate separate sections or an appropriate average; do not let a thin spot fall below the design requirement.
For weight, US short tons = matching volume in cubic yards × supplier-confirmed short tons per matching yard. Landscape Barn quotes a rough 1.3–1.5 tons-per-yard range, but that does not establish every product’s moisture state, volume basis or ton unit.2 This guide therefore labels mass factors as selected examples, not guaranteed stone densities. A handling reserve and a loose-to-compacted conversion are separate decisions; no automatic 5–10% settling multiplier is used.
| Shed footprint | Pad with selected 1-ft extension | Volume at selected 4 in | Volume at selected 6 in |
|---|---|---|---|
| 8 × 8 ft | 10 × 10 ft | 1.234568 cu yd | 1.851852 cu yd |
| 8 × 10 ft | 10 × 12 ft | 1.481481 cu yd | 2.222222 cu yd |
| 10 × 12 ft | 12 × 14 ft | 2.074074 cu yd | 3.111111 cu yd |
| 12 × 16 ft | 14 × 18 ft | 3.111111 cu yd | 4.666667 cu yd |
Table extension and depths are calculation inputs. Volumes represent the stated layer, not an already-converted loose order or structural approval.
Three checked examples
1. An 8 × 10-foot shed with a selected loose layer
A selected 1-foot extension on each side gives a 10 × 12-foot pad. At a selected 4-inch loose layer, volume is 120 × 4 ÷ 12 = 40 cu ft = 1.481481 loose cu yd. A hypothetical matching 1.4 US short tons per loose yard gives 2.074074 short tons. This is not rounded down to a 2-ton order.
2. Keep a chosen reserve separate
A selected 12 × 14-foot pad with a selected 6-inch loose layer contains 84 cu ft = 3.111111 loose cu yd. If you independently choose a 10% handling reserve, the order basis becomes 92.4 cu ft = 3.422222 loose cu yd, or 4.791111 US short tons at a matching hypothetical 1.4 factor. This reserve is an example input, not a compaction allowance or a universal recommendation.
3. Two dimensions can give the same volume
A 14 × 18-foot pad at a selected 4-inch layer contains 252 × 4 ÷ 12 = 84 cu ft = 3.111111 cu yd. That is the same geometric volume as the 12 × 14-foot, 6-inch layer above before its chosen reserve. Equal volume does not mean equal load performance or identical suitability.
Material-cost benchmark*
GoodGravel’s page is still labeled September 2026. It reports national sample medians of $24 per ton for crusher run (middle half $15–$39) and $30 per ton for crushed stone (middle half $22–$49), material only before delivery.5 Its sample uses published supply-yard prices and leans toward landscape yards because most quarries do not publish prices. These categories are not proof of the price of your exact specified shed stone.
At the selected 2.074074-ton example quantity, the material-only arithmetic is $49.78 at $24/ton or $62.22 at $30/ton. Do not choose the wrong product merely because one category median is lower. Verify the supplier’s ton basis, minimum order, sales increment, delivery, tax, excavation, perimeter, fabric and installation in a delivered quote.
*National planning benchmark, not a guaranteed local price. The cited source reports medians, not arithmetic averages. Prices are from its September 2026 published-price sample; verify a current local quote before purchasing.
FAQ
Can I use pea gravel?
Site Prep does not use rounded river stone for its shed pads, favoring crushed stone. Hello Gravel also warns against pea gravel as a primary base, despite contradictory pea-gravel instructions elsewhere on that page.1, 3 Do not substitute it without an approved system.
Is clean stone incapable of forming a firm pad?
No universal claim is justified. Site Prep specifically uses and compacts clean crushed stone in its system.1 Confirm the project specification instead of equating “clean” with “always unstable.”
Should I add sand on top?
Hello Gravel describes a sand leveling course, while other cited systems differ.3 Do not add a sand layer simply to combine competing web recipes. Ask the shed maker or installer for the required complete system.
Is a 10% extra order enough for compaction?
Not established here. The order needs a defined loose-to-compacted basis when the target is finished volume. A separately chosen handling reserve does not supply that conversion.
Related tools and guides
Shed-base material guide | Shed pad size chart | Gravel calculator | Yards and US short tons converter | Crushed-stone size guide | Pea gravel vs crushed stone
Sources
- Site Prep: Shed and Garage Base FAQs (installer system, floor types, stone, fabric and footprint)
- Landscape Barn: How Much Stone Do I Need for a Shed Base? (supplier depth, clean stone, fabric and rough density)
- Hello Gravel: Shed Base Gravel (supplier page with material/layer contradictions retained as caveats)
- Sheds by Fisher: Gravel Shed Bases (builder page with conflicting clean-stone advice)
- GoodGravel: Gravel Prices by State, September 2026 (published-yard sample medians, material only)