Gravel vs Concrete Shed Foundation: Which Is Better?

Quick answer: For a typical backyard storage shed, a compacted gravel pad is the best foundation: it costs a fraction of a concrete slab, drains water away from the floor, and stays level for decades. Choose a concrete slab for workshops, garages, and anything with vehicles or heavy machines. Blocks or piers are good on slopes, and skids on timbers work for small, light sheds.

This post compares foundation types. If you've already settled on gravel and want to know which stone to buy, read Best Gravel for a Shed Base. For the step-by-step build, see How to Build a Gravel Shed Pad.

What Are the Main Shed Foundation Options?

There are five common ways to support a shed. They split into two groups: on-grade foundations that spread the load across the whole footprint (gravel pad, slab, pavers) and point-load foundations that carry the shed on a few spots (blocks, piers, skids).

Foundation	How it works	Relative cost	Drainage	DIY friendly?	Typical life
Compacted gravel pad	4 to 6 in of crusher run in a timber or block frame	Low	Excellent	Yes	20+ years
Concrete slab	4 in poured concrete, usually with mesh or rebar	High (several times a gravel pad)	Fair, depends on grade	Hard, often hired out	30+ years
Concrete blocks or deck blocks	Solid blocks under the floor frame at set spacing	Low	Good (air under the floor)	Yes	15 to 25 years
Piers or posts	Concrete piers or ground screws below frost line	Medium	Good	Moderate	25+ years
Skids on timbers	Pressure-treated runners set on the ground or on gravel	Lowest	Poor if on dirt	Yes	5 to 15 years
Pavers	Patio pavers on a sand and gravel base	Medium	Good if base is right	Yes, slow	15 to 25 years

Is a Gravel Pad or a Concrete Slab Better for a Shed?

For most sheds, gravel wins. Here's why it holds up so well:

• Drainage. Water drains down through the pad instead of pooling against the floor framing. Rot starts where wood stays wet, and a gravel pad keeps the bottom of the shed dry.
• Forgiveness. If the ground moves a little, you can re-level the shed or top up the gravel. A cracked slab is permanent.
• Cost and time. Two people can build a gravel pad in a day with a rented plate compactor. A slab needs forms, reinforcement, a concrete truck (often with a minimum load charge), and finishing skills.
• Prefab friendly. Most prefab and rent-to-own shed dealers set buildings on gravel pads all day long.

A slab wins when the floor itself matters:

• Workshops with heavy tools, table saws, or welders
• Garages, tractor sheds, or anything you drive into
• Buildings where you want a sealed, sweepable floor or plan to finish the interior
• Sheds without their own floor, where the slab is the floor

One middle option: a gravel pad first, then a slab later. A compacted crusher run pad is exactly the base a slab should sit on, so the work isn't wasted if you upgrade.

What Drives the Cost of Each Foundation?

We won't quote numbers here because prices vary by region and change often, but the cost drivers are predictable.

Foundation	Main cost drivers
Gravel pad	Tons of crusher run, frame timbers or block, compactor rental, delivery
Concrete slab	Ready-mix volume, minimum load fees, forms, rebar or mesh, base gravel, finishing labor, possible permit
Blocks or piers	Number of blocks, a gravel pad or footing under each one, more leveling time
Skids on timbers	Lumber only, but shorter life and more re-leveling
Pavers	Pavers, sand, base gravel, and a lot of labor hours

Note that a slab still needs a gravel base under it. So a slab is roughly "a gravel pad plus concrete on top," which is why it always costs more.

To size the gravel part, a 12x14 pad (for a 10x12 shed) at 4 inches compacted is about 2.1 cubic yards, or roughly 3 tons of crusher run at 1.4 tons per cubic yard. Plug your own size into our gravel calculator.

How Do Drainage, Frost, and Settling Compare?

Drainage is the single biggest factor in how long any shed foundation lasts.

Gravel pad: Water passes through and away. In freeze-thaw areas, a well-drained pad has little trapped water to freeze, so heave is minimal. If it does move, it moves evenly.

Slab: Concrete itself doesn't drain. If it sits on wet clay with no gravel base, water collects underneath, freezes, and lifts the slab unevenly. Cracks follow. Done right (compacted gravel base, edges above grade), a slab is very stable.

Blocks and piers: Air under the floor is a plus. The weak spot is the soil under each block. Blocks set on bare dirt sink at different rates, and the shed racks out of square. Set each block on a compacted gravel base, or pour piers below your local frost line.

Skids on dirt: The worst case. The runners sit in damp soil, soak up water, and rot. Expect settling within a couple of years.

East Tennessee note: our red clay holds water, we get heavy rain, and many lots sit on slopes or karst (limestone with sinkholes). That combination punishes foundations that trap water. A gravel pad on clay should be 6 inches deep, sometimes with a layer of RCA #57 at the bottom for drainage. If water already pools where you want the shed, read our standing water drainage guide first.

Do You Need a Permit for a Shed Foundation?

Rules vary by city and county, so check locally before you build. General patterns:

• Small sheds on gravel or blocks are often exempt from building permits, though setback and easement rules still apply.
• Poured slabs are more likely to count as a permanent structure, which can trigger a permit, inspection, or property tax reassessment.
• Larger buildings (often anything over a set square footage) usually need a permit no matter the foundation.
• HOAs may have their own rules about foundation type and placement.

Also call 811 before you dig for any foundation.

Which Foundation Fits Your Shed Size and Use?

Weight and use matter more than footprint. A 10x12 storage shed full of garden tools is light. The same size building with a riding mower, a workbench, and a loft full of lumber is not.

Shed type	Best foundation	Runner-up	Notes
Small resin or metal shed (under 8x10)	Gravel pad, 4 in	Pavers	Many kits need a flat, level base for the floor to lock together
Wood storage shed, 8x10 to 12x16	Gravel pad, 4 to 6 in	Blocks on gravel	Gravel keeps the floor framing dry
Large prefab or barn, 12x20 and up	Gravel pad, 6 in	Concrete slab	Dealers usually prefer gravel for delivery
Shed on a sloped lot	Blocks or piers	Gravel pad with retaining frame	Level with a frame or piers first
Workshop with heavy tools	Concrete slab on gravel base	Gravel pad, 6 in, with a wood floor	Slab gives a solid floor for machines
Garage or tractor shed	Concrete slab on gravel base	Gravel pad, 6 to 8 in	Vehicles need a hard, durable surface
Chicken coop or kennel	Gravel pad, 4 in	Blocks	Easy to clean around and drains well

Which Lasts Longest?

A concrete slab built on a proper gravel base can outlast the shed on top of it. But a well-built gravel pad also lasts the life of a typical shed, often 20 years or more, and it's easy to refresh. Blocks and pavers last well if the base under them was compacted. Skids on bare ground are the short-term option.

The pattern is clear: every long-lasting shed foundation starts with compacted gravel. Whether you stop there or pour concrete on top is a question of use and budget.

What Gravel Should Go Under Any Shed Foundation?

Use compacted crusher run (also called crush and run or dense-graded base). The fines lock the angular stone into a hard layer. RCA crusher run, made from recycled concrete, does the same job and packs very hard. Use #57 only as a drainage layer under crusher run, not as the surface the shed sits on. The full comparison is in Best Gravel for a Shed Base, and crusher run vs #57 covers the difference between the two stones.

Quick tonnage reference for pads 1 ft larger than the shed on each side:

Shed	Pad	4 in compacted	6 in compacted
8x10	10x12	~2.1 tons	~3.1 tons
10x12	12x14	~2.9 tons	~4.4 tons
12x16	14x18	~4.4 tons	~6.5 tons

Order 15 to 20 percent extra for compaction. For other sizes, use the gravel calculator.

Get Crusher Run for Your Shed Foundation

Going with gravel, or building the base for a future slab? We sell RCA crusher run and RCA #57 at 245 Brookdale Rd, Maryville, TN. Load out in your own truck or get it delivered through our trucking service. Open Mon-Fri 7 AM to 5 PM and Saturday 8 AM to noon.

Call (865) 999-0857 for current pricing on RCA and delivery.

Tearing out an old slab to make room? Clean concrete drop-off is free at our yard. See free concrete drop-off.