#4 Crushed Stone: the 3/4 to 1-1/2 Inch Layer for Soft Ohio Ground

Nearly every load of it is ordered by somebody who has already bought gravel twice. A field entrance or a lane bottom on till clay swallows a smaller stone: the load goes down, looks right for a month, and by the second wet spell the surface has worked its way into the muck and the ruts are back. The conclusion people draw is that they need more gravel. The conclusion the ground is offering is that they need bigger gravel, low down, where it can bridge instead of sink.

That is the fault this grade corrects. It is not a surface and it is not a finish. It is a bottom.

#4 crushed stone against #57, 411 stone and railroad ballast

Four grades get compared against each other on Ohio jobs and each one does a different thing.

#57 limestone is clean stone at 3/16 to 1 inch. It drains well, it is easy to handle, and on genuinely soft ground the pieces are small enough to be pushed down into it. It belongs in trenches and drainage layers rather than at the bottom of a lane that a loaded truck uses.

411 stone runs up to about an inch with fines through it, so it compacts into a firm surface. That is its strength and its limit: a compacted material with fines will not let much water through, so it goes on top of a drained bottom rather than instead of one.

Railroad ballast runs roughly 1 to 2.5 inches, so it overlaps this grade and carries more of the larger sizes. For an equipment yard it is the heavier answer. For a trench or a drainage run where you still want to handle the stone with a shovel, the #4 grade is easier to work with.

This grade sits between them. Big enough to bridge soft ground and hold its voids under a wheel, small enough to place by hand, open enough to pass a lot of water.

Where it earns its keep: a barn pad, a field gate, the bottom of a wet lane

A pole barn or equipment pad on glacial till is the clearest case. The pad has to stay level under concentrated loads through a freeze cycle, and level means dry, which means the water under the pad needs a layer it can move through. The coarse stone goes down first over the prepared subgrade, and a compacted 304 aggregate base goes on top where the finished pad needs to be firm and even.

A field gate or a construction entrance on the old lake plain in the northwest is the second. That black, sticky ground turns greasy the moment it rains, and a coarse angular stone over a geotextile gives equipment something to climb onto and knocks the mud off tires before they reach the road.

The bottom of a wet lane is the third. Where a lane crosses a swale or a spring seep and has never held its shape, the repair is not another top dressing. Cut out the soft material, lay the coarse stone as the bottom lift, and build the running surface back on top of it.

A dry creek line and a fire pit surround are where the size works against you

Two jobs it gets ordered for that suit something else.

A dry creek bed is meant to look like a watercourse, so it wants rounded, varied stone. A single-size crushed grade reads as construction material in a garden, and the sharp faces show every broken edge. River rock is the material for the bed itself, with the coarse crushed stone hidden underneath as the drainage layer if the channel carries real water.

A fire pit surround is a seating and standing area, and 3/4 to 1-1/2 inch angular stone is miserable to stand on and rolls a chair leg. The surround wants something that compacts flat, such as screenings over a base, with the coarse stone kept out of sight.

How thick the layer goes under a 24 by 36 equipment pad

Depth here is about bridging, not about strength. A thin scatter of coarse stone pushed into soft clay is wasted; the layer has to be thick enough that the pieces bear on each other rather than individually on the mud. On workable till, 4 to 6 inches as a bottom lift is the usual call. On the sticky flats where a boot sinks, 8 inches and a geotextile beneath it, because the fabric is what stops the clay squeezing up between the pieces and filling the voids.

Ohio frost reaches around 32 inches through much of the state and deeper in northern counties, well below anything you are placing, so the point of the layer is never to get under the frost. It is to make sure there is no water sitting in the ground when the frost arrives.

Tons for a 24 by 36 pad and a field entrance at the gate

Take a hypothetical equipment pad, 24 by 36 feet, with a 6 inch bottom lift.

• Area: 24 x 36 = 864 square feet
• Depth: 6 inches = 0.5 feet
• Volume: 864 x 0.5 = 432 cubic feet
• Cubic yards: 432 / 27 = 16 cubic yards
• Tons: this site figures the #4 and ballast family at roughly 2,900 lb per cubic yard, about 1.45 tons per yard, so 16 x 1.45 = about 23 tons

And a hypothetical field entrance, 20 feet wide and 40 feet back from the road, at 8 inches:

• Area: 20 x 40 = 800 square feet
• Depth: 8 inches = 0.667 feet
• Volume: 800 x 0.667 = 533 cubic feet, or 533 / 27 = 19.8 cubic yards, about 29 tons at the same approximate weight

Those figures are for the coarse layer alone. Whatever finishes on top is a separate calculation, and on a pad it is usually the bigger of the two. Run your own numbers through the stone calculator before you commit to a quantity.

Ordering it, and where the piles should land

Pick the quantity and the delivery date on this page. Delivery is arranged at checkout once the ZIP code goes in, and the truck needs a clear run and room to raise a bed, which on a farm lane means thinking about the gateway and the overhead wires before the day.

Coarse stone is worth splitting into two drops if the work is spread out, one at the gate and one where the lane goes soft, because moving 3/4 to 1-1/2 inch stone 200 feet with a bucket costs more time than the second drop is worth. Mark where you want each pile, and keep them off the spot you are about to excavate. Ohio Rock Supply can talk through an awkward access on the contact page if the lane is tight.