3/4" Crushed Stone: Angular Clean Rock for Missouri Pads and Backfill

The order that comes up most often on this ground is the one that follows a wet spring. A gate entrance churned to soup by a tractor, a parking spot beside a shop that has started rutting, a lane grade climbing out of a hollow that loses its surface to the ditch every time a storm gets up. What those jobs share is that nobody needs a prettier surface. They need something underneath with enough angle on the faces to lock together and enough space between the pieces that water keeps moving. That is what 3/4" crushed stone is for.

Three quarter inch clean: what people are asking for when they say it

The verified spec is short.

Around here it is usually called three quarter inch clean, and clean is the word doing the work. There is no binding dust running through it, so the layer holds together by interlock: broken faces wedged against broken faces. Roll it and the pieces seat, but they never cement into a slab the way a fines-bound material does.

Keep that distinction straight and the whole product range falls into order. Base Rock and Crusher Run carry fines, pack hard and can take traffic on top. This one carries loads through interlock and lets water through at the same time. And Drain Rock, which overlaps it in size, is washed and runs coarser at the top end, bought specifically so a buried run keeps flowing.

Where 3/4" crushed stone belongs on a hobby farm, job by job

The wall backfill role is the one most often skipped and most expensive to skip. Water standing behind a block or timber wall pushes on it every wet spring, and a column of clean stone from the footing up, capped so surface water cannot run straight into it, gives that water a way out.

An RV pad, a swing set and a raised bed: one yes and two noes

A pad for an RV or a boat trailer is a proper use, with one condition: this stone is the layer underneath, not the layer on top. Build it in compacted lifts over a prepared subgrade and put a bound surface over it if you want something that does not roll under a tire.

A swing set fall zone is the wrong job entirely. Angular three quarter inch stone is sharp, it holds an edge, and it is unpleasant to land on. Shredded Mulch is what goes in a fall zone.

A raised vegetable bed takes Garden Soil inside the frame. The only stone in that picture belongs in the path between the beds, and even there a smaller grade walks better.

Karst, claypan and what sits under the stone when the ground is soft

The subgrade decides the depth, and it changes a lot across this state.

On cherty Ozark ground over limestone or dolomite there is often firm material a spade's depth down, and a shallower layer of stone will do. What that ground asks instead is where the water goes, because sinkholes and openings in the bedrock mean runoff can disappear locally and reappear somewhere you did not choose. Do not build a pad so it drains straight into one.

On the northern claypan and the tight clay of the west-central prairies, water perches from late fall into spring and the ground under it stays soft. Stone tipped straight onto that gets pushed into the clay and vanishes. Separation fabric first, then a bridging course of something coarser such as #4 Crushed Stone, then this material over the top.

On Bootheel silt and sandy loam the ground dries sooner but has little strength when it is wet, so the same logic applies at a lighter scale.

Frost depth is moderate here and set by the local building code, deeper north and around the Kansas City side than down in the southern Ozarks. Footing depth is a code question, not a stone question, so check it locally before anything is poured.

Tons for a 12 by 30 trailer pad and a 40 foot wall backfill

Two hypothetical jobs, worked through.

A trailer pad 12 by 30 feet with 6 inches of stone: 12 x 30 is 360 square feet, and 6 inches is 0.5 feet, so 360 x 0.5 gives 180 cubic feet. Divide by 27 and that is 6.67 cubic yards. This site publishes about 2,800 lb per cubic yard for the #57, #67 and 3/4 inch crushed stone family, roughly 1.40 tons to the yard and approximate, so 6.67 x 1.40 comes out near 9.3 tons.

A drainage chimney behind a 40 foot wall, one foot wide and 3 feet tall: 40 x 1 x 3 is 120 cubic feet, 4.44 cubic yards, about 6.2 tons.

Both figures are for the compacted layer, so add a little for the drop under a plate or a roller. The stone calculator repeats the sums with depth guides and a five percent allowance that is on by default.

Getting a loaded truck onto a hilltop lot before the ground turns

Access is the part of a stone order that goes wrong, and on this ground it usually goes wrong twice: once in spring when the approach is soft, and once in midwinter when a rutted approach freezes solid in the shape it dried in.

Late spring through fall is the easier window for this work, between the wet season and the first hard freeze. Pick a drop spot the truck can reach and turn in without crossing the part of the yard you are about to build on, and think about whether the pile can sit at the top of a grade so the spreading runs downhill.

Delivery is arranged at checkout from your ZIP code and the truck needs clear access to somewhere it can tip. Missouri Rock Supply takes the ZIP at that point, so if the lane is narrow or the turnaround is tight, sort it out through the contact page before you put a date on the load.