#10 Stone Screenings: The 1/4 Inch Minus That Packs Flat

Run a handful of screenings through your fingers and the first surprise is how little of it looks like stone. What you are holding is gray grit with flecks up to about a quarter of an inch in it, and it leaves dust on your palm. Squeeze a damp handful and it holds its shape; that is the property the whole product is bought for. Around the country the pile behaves differently before you have even spread it. Loads delivered into gulf-coast humidity arrive damp and clump under the shovel. In a dry Rocky Mountain summer the same material blows off the top of the wheelbarrow.

Stone screenings are the fine end of the crushing process: 1/4 inch minus angular particles and stone dust, with nothing large in the mix. Everything below follows from that gradation.

What the gradation actually gives you

Three things, and it is worth being exact about them because the material is often bought for a fourth thing it cannot do.

• It fills voids. Fine angular particles find their way into gaps and low spots, which is why it screeds to a flat plane so easily.
• It binds when damp and compacted. Moisture plus a plate compactor pulls the particles together into a firm, dense layer that holds a level.
• It does not drain. Those same fines close the voids that water would otherwise move through. Anything that needs flow wants an open-graded stone instead.

Job by job, where stone screenings earn their place

Fines, frost and humidity: what changes between regions

A layer of fines holds a little water by nature, and what happens to that water depends where you are.

In the frost belt, water held in a bedding layer freezes and lifts the units above it, which is why northern paver work is usually built over a thick, free-draining compacted base with only a thin bedding course on top. Across the southern half of the country the issue is rain volume rather than freezing: water that cannot pass through a compacted layer has to be given a route around it, or it finds the edges and undermines them. On wet coastal ground, a layer of fines placed straight onto a saturated subgrade will pump and wobble under load no matter how well it was rolled.

Why a new lawn is not a screenings job

This material gets ordered for lawn preparation more often than it should be. It contains no organic matter, holds almost no plant-available water and compacts hard, which is close to the opposite of what grass roots need. Use Top Soil for a new lawn surface, Garden Soil for beds, and Fill Dirt to bring a low area up before either of them goes on. The only honest role for screenings near a new lawn is leveling the hard surfaces beside it: the path, the pad or the edging course.

Measuring a hot tub pad and a 40 foot path in cubic yards

Both are hypothetical examples. This site's calculator figures screenings at about 2,900 lb per cubic yard, or 1.45 tons per yard, so the tonnages below are approximate; the stone calculator will run the same conversion on your own dimensions.

Hot tub pad, bedding course. 8 by 8 feet at 1 inch over a compacted base: 8 x 8 = 64 square feet. 64 x 1 / 12 = 5.33 cubic feet. 5.33 / 27 = 0.20 cubic yards, which is about 0.29 tons.

Compacted garden path. 40 feet long by 3.5 feet wide at 2 inches: 40 x 3.5 = 140 square feet. 140 x 2 / 12 = 23.33 cubic feet. 23.33 / 27 = 0.86 cubic yards, and 0.86 x 1.45 = roughly 1.25 tons.

A cubic yard spread 1 inch thick covers about 324 square feet, and at 2 inches about 162 square feet. Bedding layers are thin, so small errors matter less in volume than in flatness; order to the nearest sensible quantity and keep the surplus for joints.

Getting the ground ready for a load of dust

Because the material is fine, where it lands matters more than with a coarse stone. A pile dumped on grass leaves a gray patch that takes a season to recover, and a pile caught by wind on a dry day spreads further than you want. Ask for the drop on a hard surface or on plastic if you have it, and plan to move it the same day.

Set the tonnage and the delivery date on this page. Delivery is arranged at checkout by ZIP code, and the truck needs clear access to a spot it can tip in without backing across soft ground. If your area is an awkward shape and you want the volume checked before ordering, the contact page takes a quote request by email.