Guides · Concrete
How to Build a Shed Base: Gravel, Concrete, or Pavers?
By the MyBuildCalcHub team · Figures verified against our audited estimating engine · Updated
The three shed bases compared
The right base depends on shed size, ground conditions, and how permanent you want it. Here's the honest trade-off:
| Base type | Cost & effort | Drainage | Best for |
|---|---|---|---|
| Gravel pad | Low, DIY-friendly | Excellent | Most sheds; sloped or damp sites |
| Concrete slab | High, permanent | Poor (sheds water off surface) | Large or heavy sheds, workshops |
| Paver base | Medium | Good | Mid-size sheds; level, finished look |
For the majority of garden and storage sheds, the gravel pad wins on cost, drainage, and forgiveness, it's the default a lot of shed manufacturers actually recommend, because a slab that traps water against a wooden shed floor invites rot.
Sizing a gravel shed base
A gravel shed base is 4 to 6 inches of compacted crushed stone, in a frame extending about a foot past the shed on each side. Crushed stone (not rounded pea gravel) is what compacts into a firm, stable pad, see crusher run vs. #57 for which product locks solid. Quantity math is straightforward: a 4-inch layer takes about 1.23 cubic yards, roughly 1.7 tons, per 100 square feet. An 8×10 shed pad (80 sq ft) at 4 inches is about 1 cubic yard, or 1.4 tons before the standard 5% aggregate allowance.
Sizing a concrete shed slab
If you're going permanent, a shed slab is typically 4 inches thick, often with a thickened edge, over 4 inches of compacted gravel. Volume follows the standard slab math, an 8×10 slab at 4 inches is 26.7 cubic feet, about 1 cubic yard or 45 × 80 lb bags before waste (our concrete calculator and coverage guide handle any footprint). At roughly a yard, this pour sits right at the point where ready-mix starts beating bags, and pouring it in one go avoids a cold joint through your shed floor.
The paver base
A paver base is really a gravel base with a finished top: 4 inches of compacted crushed stone, then about an inch of leveling sand, then pavers set tight. It gives you the drainage of gravel with a flat, finished surface, at more effort than a loose pad but less cost than a slab. Size the crushed-stone layer exactly as you would a gravel pad; the sand and pavers are the only extras. Whichever base you choose, clear and level the ground first and pad every aggregate order with the standard 5% waste allowance, edges and settling always take a little more than the tape says.
Preparing the ground first
Every base type fails the same way when the ground under it is wrong, so groundwork comes before the first stone. Strip off sod and organic topsoil down to firm subsoil, organic material rots and settles, taking your level pad with it. Level the footprint, then build in a slight, deliberate fall of about an inch over the length so water runs off rather than pooling under the shed. On soft or clay-heavy ground, a layer of landscape fabric under the gravel stops the stone from migrating down into the soil over the years, the same failure that ruts a gravel driveway. Extend the prepared area about a foot beyond the shed on every side: the base should be slightly larger than what it carries, never smaller, so no edge of the shed floor overhangs unsupported ground.
Frequently asked questions
What is the best base for a shed?
The best base for most sheds is a compacted gravel pad, 4 to 6 inches of crushed stone contained in a timber frame. It drains well, tolerates minor ground movement, and costs far less than concrete. A poured slab is better only for large, heavy sheds or workshops where a permanent, level floor matters.
How thick should a gravel shed base be?
A gravel shed base should be 4 to 6 inches of compacted crushed stone over a cleared, leveled subgrade. Four inches suits most garden sheds; step up to 6 inches for larger sheds or soft, poorly draining ground. Compact it in layers so the pad doesn't settle unevenly under the load.
Do I need a concrete slab for a shed?
A shed does not need a concrete slab in most cases, a compacted gravel pad supports typical garden and storage sheds well and drains far better. A slab makes sense for large sheds, workshops with heavy equipment, or when you want a finished permanent floor, but it costs more and takes more work.