Driveway Gravel

Driveway gravel starts as quarried rock, most commonly limestone, granite, or trap rock, that is mechanically crushed and then screened into size grades. The grade numbers, like #57 or #67, refer to the sieve sizes used to sort the stone, not a universal quality scale. #57 stone runs around 3/4 in and is typically used as a base or sub-base layer because its larger, more angular pieces lock together and carry load well. #67 stone is a slightly finer blend, from 3/8 in up to 3/4 in, and works well as a top coat because it packs down tighter and gives a smoother driving surface. Crush-and-run, sometimes called quarry process, keeps the stone dust in the mix instead of screening it out, which makes it compact into an extremely hard, dense base layer with less drainage. Color comes from the parent rock, so gray-tan usually means limestone, speckled gray-pink-black usually means granite, and dark blue-gray usually means trap rock.

Start by removing topsoil and any organic material down to a firm subgrade, then compact that soil before adding any stone. For a new driveway, spread a 4 to 6 in layer of larger crushed stone or crush-and-run first and compact it in passes, not all at once. Add a second layer of the same material if you need more depth, compacting each lift separately, until you reach 8 to 12 in of base. Finish with a 2 to 4 in top coat of #57 or #67 stone, graded and crowned slightly so water sheds to the sides instead of pooling in the center. Geotextile fabric laid between the soil and the first stone layer keeps the gravel from sinking into the subgrade over time, which is one of the more common causes of a driveway that seems to disappear into mud after a year or two. Expect the finished material to compact down 10 to 20 percent from its loose, delivered volume.

Compared with pea gravel. Pea gravel is smooth and rounded, comfortable underfoot but useless as a driveway surface because it does not interlock or compact under tire weight. It scatters and gets pushed into ruts and lawn edges within weeks, where angular driveway gravel stays put and forms a stable, driveable crust.

Compared with crush-and-run. Crush-and-run keeps its stone dust and fines in the mix, so it compacts into a dense, hard base layer but drains poorly on its own. It belongs under a cleaner top coat of #57 or #67 stone, not as the finished driveway surface, where you want visible drainage and a defined stone size.

How much driveway gravel do I need. Measure length times width times depth in feet, divide by 27 to get cubic yards. As a shortcut, 1 cubic yard covers roughly 100 to 110 sq ft at a 3 in depth, or use the coverage table above for other depths. A 12 ft by 50 ft driveway at 4 in deep needs close to 8 cubic yards for a top coat alone, more if you are also building the base layer from scratch. Always order slightly more than the math says to cover compaction loss.

How driveway gravel is sold and delivered. Driveway gravel is sold in bulk by the cubic yard or by the ton, not bagged, since driveway quantities are large. Delivery is typically dumped in a pile at the driveway or curb, so you will want clear access for a dump truck and a plan for moving material from the pile to where it is being spread. Larger jobs often order sub-base and top-coat stone as separate deliveries.