Best Gravel for a Shed Base: Crusher Run vs #57 vs RCA

TL;DR: Use compacted crusher run for a shed base, virgin limestone or recycled concrete (RCA). It locks into a hard, level pad. #57 drains well but stays loose, so use it only as a drainage layer under crusher run on wet sites. Skip pea gravel and river rock: round stone rolls and never locks up.

This post is about one decision: which gravel to put under your shed. If you've already picked the material and want the build steps, go to How to Build a Gravel Shed Pad: Step-by-Step.

Shed Base Gravel Compared

Gravel	What it is	Compacts?	Drainage	Shed base verdict
Crusher run (limestone)	Angular stone, ~3/4" to 1.5" minus, fines included	Yes, very hard	Good (sheds water off the surface)	Best all-around choice
RCA crusher run	Crushed concrete, 3/4" minus, fines included	Yes, very hard, lightly self-cements	Good	Best value choice
#57 stone	Clean angular ~3/4" to 1", no fines	No, stays loose	Excellent (water drains straight through)	Drainage layer only
RCA #57	Clean crushed concrete ~3/4" to 1"	No	Excellent	Drainage layer only
Pea gravel	Small round stone	No, rolls	Good	Avoid
River rock	Large round stone	No	Good	Avoid
Sand	Fine particles	Somewhat	Poor in clay, washes out	Avoid as a base
Fill dirt / bank run	Mixed soil and stone	Inconsistent	Poor	Avoid

Crusher Run: The Standard

Crusher run goes by a lot of names: crush and run, dense-graded aggregate (DGA), 21A, base stone. The key is the fines. Stone dust fills the gaps between larger angular pieces, and when you compact it, the whole layer locks into something close to a soft slab.

Why it wins under a shed:

• Holds level under skid and block loads
• Screeds flat for a square, plumb building
• Sheds water off the surface when the pad is pitched slightly
• Easy to top up years later

Downside: water moves through it slower than clean stone. On well-drained ground that doesn't matter. On wet clay, add a drainage layer (see below).

RCA Crusher Run: Same Job, Usually Less Money

RCA crusher run is recycled concrete crushed to 3/4" minus with the fines left in. Under a shed it performs like limestone crusher run, and often packs harder because leftover cement in the old concrete lightly binds the layer over time.

• Pros: compacts hard, very angular, generally costs less than virgin stone, made locally from recycled concrete
• Cons: grayer color with occasional brick or tile flecks, which nobody sees once the shed is on it

We sell RCA crusher run and RCA #57 at our Maryville yard. More on the material in What Is RCA Gravel?.

#57 Stone: Great Drainage, Bad Surface

#57 is clean, angular stone around 3/4" to 1" with no fines. Water pours straight through it. That's its strength and its weakness: with nothing filling the voids, it never locks into a solid surface. Skids and blocks can rock and settle as the stones shift.

Where #57 earns its spot: as the bottom layer on wet or clay sites, 2 to 3 inches of #57 under compacted crusher run. Water drains out of the pad while the shed sits on a firm surface.

For more on this pair, see crusher run vs #57. The same logic applies under a shed as under a driveway.

Pea Gravel and River Rock: Skip Them

Round stone acts like ball bearings. It looks nice around a shed, but under one it shifts every time weight moves, and the building goes out of level. If you want pea gravel for looks, use it as a decorative border outside the pad, not under the skids.

Best Gravel by Shed Size and Type

Shed or building	Recommended base	Compacted depth
Small storage shed, 8x8 to 8x10	Crusher run or RCA crusher run	4 in
Standard shed, 10x12 to 12x16	Crusher run or RCA crusher run	4 in (6 in on soft soil)
Large prefab, 12x20 and up, or lofted barn	Crusher run or RCA crusher run	6 in
Garage or workshop with vehicles	Crusher run or RCA crusher run, #57 drainage layer if wet	6 to 8 in
Shed on blocks or piers	Crusher run under each block, or a full pad	4 to 6 in
Chicken coop, kennel, small building	Crusher run	4 in

Best Gravel by Soil and Drainage

Site condition	What to use
Firm, well-drained soil	Crusher run alone, 4 in
Red or gray clay (common in East TN)	Crusher run, 6 in; consider 2 to 3 in of #57 underneath
Low spot or standing water after rain	#57 drainage layer under crusher run, plus pitch or a drain to daylight
Sloped lot	Crusher run with a timber or block retaining edge on the low side
Sandy soil	Crusher run, 4 in; woven geotextile helps keep layers separate

If water already pools where the shed is going, fix that first. Our standing water drainage guide covers the options.

Pad Basics (Short Version)

Whatever gravel you choose, the pad itself follows a few rules:

• Make the pad 1 ft bigger than the shed on every side (a 10x12 shed gets a 12x14 pad)
• Strip topsoil to firm subgrade before adding stone
• Frame the edges with timbers or block
• Compact in 3 to 4 inch lifts with a plate compactor

The full layout, excavation, framing, compaction, leveling steps, and tons-needed tables are in How to Build a Gravel Shed Pad. For a quick tonnage number, use our gravel calculator.

Our Pick

For nearly every backyard shed in East Tennessee: compacted RCA crusher run, 4 to 6 inches deep, with a #57 drainage layer underneath only if the site is wet. You get a hard, level base, and it generally costs less than virgin crusher run.

Pick up at 245 Brookdale Rd, Maryville or get it delivered (see trucking). Open Mon-Fri 7 AM to 5 PM and Saturday 8 AM to noon. Call (865) 999-0857 for current RCA and delivery pricing, or browse aggregate for sale.