Gravel vs. Concrete Shed Foundation: Which One You Actually Need

Cost is usually the first question people ask about shed foundations, but it is the wrong first question. Size, soil drainage, and local frost depth decide which foundation type is actually appropriate — cost only matters once you know which options are on the table.

Gravel pad: fast, cheap, and fine for most small sheds

A compacted gravel pad under pressure-treated skids is the standard choice for sheds up to roughly 120–150 square feet in most climates. It drains well, it is quick to build in a weekend, and it costs a fraction of a poured slab. Its main limitation is that it is an on-grade foundation — it sits on top of the ground rather than below the frost line.

When concrete becomes the right call

A poured concrete slab or frost-proof footing makes more sense once a shed gets larger, heavier, or is meant to be permanent — particularly in areas with a deep frost line, where ground movement during freeze-thaw cycles can shift an on-grade foundation over a few winters. Concrete is also the more common requirement once a shed crosses into "needs a building permit" territory, since inspectors often specify a permanent foundation at that size.

The soil question nobody checks first

A gravel pad on soil that does not drain well can trap water under the shed instead of shedding it, which defeats the purpose of the gravel in the first place. Before committing to gravel, check how the site drains after a heavy rain — standing water for more than a day or two is a sign the site needs grading or a different foundation approach.

A simple way to decide

• Small, movable, non-permanent shed on well-drained soil → gravel pad.
• Large, permanent, or code-required structure → poured concrete or frost-proof footings.
• Anywhere in between → check your local frost depth and permit threshold before deciding.

Not sure a permit even applies to your build? See do you need a permit to build a shed first.