Limestone Screenings

Limestone screenings are the fine fraction that falls through the screens at a quarry when larger limestone is crushed into gravel and base stone. Rather than being a waste product, this fine material is bagged or sold in bulk on its own because the mix of dust and small aggregate compacts unusually well. Gradations are typically labeled by their top size, such as 3/8 minus or 1/4 minus, meaning all particles pass through that screen size, with everything from dust up to that maximum mixed together. This continuous gradation, rather than a single uniform particle size, is exactly what lets the material lock together under compaction. Regional naming varies by supplier and market. In much of the Midwest and Ontario, this product is called limestone screenings. In the Northeast, a similar fine crushed-rock product is more often sold as stone dust, though stone dust can come from granite or trap rock instead of limestone. If your project calls for that Northeastern product specifically, see our stone dust page for details on sourcing and paver-setting use.

Compaction quality depends on installing in layers, not dumping the full depth at once. Spread screenings in lifts of 2 to 4 inches and compact each lift with a plate compactor before adding the next, working up to a total base depth of 4 to 6 inches for patios, paths, or light driveways. Skipping this step and compacting one thick lift leaves the lower material loose, which shows up later as settling or soft spots. Over clay or poorly draining native soil, lay geotextile fabric under the base first. The fabric keeps the screenings from being pumped into the soil under load and moisture, which otherwise causes heaving and soft spots after freeze-thaw cycles. Order 15 to 25 percent more material than the final compacted volume requires, since that's the typical shrinkage from loose to compacted state. On slopes, add edging and consider a coarser stone or additional fabric, since screenings can erode under heavy runoff even after they've compacted into a hard cap.

Compared with crushed stone or gravel (#57, #8 clean stone). Clean crushed stone is open-graded with almost no fines, so it drains fast and stays loose underfoot. Limestone screenings contain fines that fill the voids between particles, letting them compact into a solid, semi-impermeable surface. Choose screenings for a stable, walkable base, and clean stone where drainage is the priority.

Compared with decomposed granite (dg). DG is crushed granite, not limestone, and typically has a warmer tan or reddish-brown tone compared to the gray or buff color of limestone screenings. Both compact similarly into firm surfaces, but DG is more common in western and southwestern regions for its natural look, while limestone screenings dominate as a functional base material in the Midwest and East.

How much do I need. Coverage runs on a simple rule: one cubic yard covers about 324 square feet at 1 inch of depth, so divide 324 by your planned depth in inches to get square feet covered per cubic yard. For a typical 3 inch path or base layer, expect roughly 100-110 square feet per cubic yard. Since screenings compact down 15 to 25 percent from loose volume, add that percentage to your order so the finished depth still meets spec after compaction.

How it's sold and delivered. Limestone screenings are sold in bulk by the cubic yard or by the ton, with weight running roughly 1.2 to 1.4 tons per cubic yard since the fines pack denser than open-graded gravel. Bulk delivery drops the material by the load at your site, which works well for base layers, barn floors, and path projects that need multiple yards. Bagged quantities are available for very small touch-up jobs but are inefficient for anything beyond that.