Gravel Delivery in South Carolina

Near the coast, the ground is young and loose. The state geologic map reads unconsolidated mud at the Charleston and North Charleston center points. Mount Pleasant's center point shows clay and sand, and Summerville's limestone and sand. Columbia's center point reads clay, sand and limestone. These are layers of sediment laid down by the sea and by rivers. Mud and clay hold water and compress under weight. Sand drains well but shifts unless it is held in place.^[1]

Upstate, the rock is old and hard. Greenville's center point reads mica schist, Spartanburg's biotite gneiss, and Rock Hill's gabbro. Schist is a layered rock that sparkles with flakes of mica. Gneiss has light and dark bands and breaks into tough, blocky pieces. Gabbro is a dark, heavy rock that cooled slowly from molten material deep underground. Quarries in hard crystalline rock like this crush it into the gray angular stone used across the state, including #57 Crushed Stone, 3/4" Crushed Stone and Road Base.^[1]

Crushed stone for a coastal drive is hauled in from inland quarries, since soft mud and sand cannot be crushed into driveway rock. Limestone in coastal layers like those at the Summerville and Columbia center points can be soft and shelly, and it rarely matches the hardness of upstate rock. Sand pits near the coast supply Fill Sand, Mason Sand and Concrete Sand.^[1]

Soil readings follow the same split. The USDA soil survey reads loamy fine sand, moderately well drained, at the North Charleston center point and loamy fine sand, somewhat poorly drained, at the Mount Pleasant center point. Summerville's center point shows loamy sand, moderately well drained. Inland, Rock Hill's reads fine sandy loam, somewhat poorly drained, and Spartanburg's sandy loam, well drained. Sandy soils make a firm base when compacted, but where they drain poorly, water can sit just below the surface after a storm.^[2]

The upstate ground sits higher. The Greenville center point stands 950 feet above sea level and the Rock Hill center point 570 feet. The South Carolina Department of Transportation writes its rules for the stone layer under state pavements in Graded Aggregate Base, Section 305, of its Standard Specifications for Highway Construction, dated 2025.^[3],[4]

Rain is heavy in every city. The weather station used for Summerville averages 52.7 inches of precipitation a year, North Charleston's 52.5 inches and Mount Pleasant's 51.6 inches. Greenville's station logs 50.7 inches, Spartanburg's 50.2 inches and Columbia's 48.1 inches. Charleston's station reads 44.3 inches and Rock Hill's 42.6 inches. Summer storms can drop a lot of water in an hour, so a yard firm at noon can be soft by evening.^[5]

Winter is mild, and cold rises with distance from the coast. The Spartanburg station counts 76 days a year at 32 F or colder and Greenville's 73 days. Rock Hill logs 51 days, Summerville 45 and Columbia 33. Near the ocean, North Charleston's station logs 22 days, Mount Pleasant's 18 and Charleston's only 6. Snow barely registers: the Spartanburg station averages 0.8 inches a year, North Charleston's 0.3 inches and Columbia's 0.2 inches. Deliveries run most of the year without weather delays from cold. Heat is the bigger summer concern. Spread and compact base stone early in the day, and wet Road Base lightly before each pass of the plate compactor so its fines bind into a firm layer.^[5]

Soft ground is the main risk for a truck. On somewhat poorly drained loamy fine sand, like the Mount Pleasant reading, the water table can sit close to the surface, and a loaded truck can sink into a lawn. Ask for the drop on the driveway or the street after rain. On low coastal lots, keep the pile off spots where water collects.^[2]

Access differs by area. Older streets in Charleston can be narrow, with tight lots, low limbs and on-street parking. Suburbs in Summerville, Rock Hill and Spartanburg tend to have wide drives. Tell Gravel Valet about gates, trees, overhead lines and soft shoulders when you order. A tarp under the load keeps stone dust off a concrete drive.^[1],[2]

Drainage leads the list near the coast. With 52.5 inches of precipitation a year at the North Charleston station and soft, low ground, water stands in many yards after a storm. A French drain of fabric, perforated pipe and Drain Rock or #57 Crushed Stone moves water to a lower spot. River Rock lines a swale or a dry creek bed and holds up where water runs fast. Raising a low spot with Fill Dirt or Fill Sand keeps water away from a slab. Riprap protects a bank where storm water leaves a pipe or meets a pond edge, since its large, heavy stones stay put where smaller rock washes out.^[1],[5]

Driveways on soft ground need a thicker base. On mud and clay, like the Charleston center point reading, lay a woven fabric first to keep the base from sinking. Add a coarse layer of #4 Crushed Stone or 1-1/2" Crushed Gravel, then compacted Road Base or Crushed Concrete, and a top of Driveway Gravel or 3/4" Crushed Stone. Crown the drive so rain runs off quickly.^[1]

Upstate drives sit on firmer ground. On the well drained sandy loam at the Spartanburg center point, the subgrade compacts firm. Red clay pockets are common in rock that weathers like gneiss and schist, and they turn slick when wet, so lay fabric under the base anyway. Asphalt Millings make a hard, dark surface that handles rain well. On a slope, add a shallow ditch or a stone trench at the top of the drive so runoff from the hill goes around it.^[1],[2]

Patios and walks come next. Set pavers on compacted Road Base and a bed of Concrete Sand or Stone Dust Screenings, then sweep Mason Sand into the joints. On the somewhat poorly drained fine sandy loam at the Rock Hill center point, add a stone trench along the low edge of a patio so water has a way out. Walkway Gravel, Pea Gravel and 3/8" Crushed Stone make paths that drain after a storm.^[2]

Gardens finish the list. Sandy coastal soil, like the loamy sand at the Summerville center point, drains fast and holds few nutrients, so work Compost and Garden Soil into new beds. Brown Shredded Mulch, Black Shredded Mulch, Red Mulch and Wood Chips hold moisture and slow weeds. River Rock suits beds near downspouts where mulch would wash away. Playground Sand fits a sandbox.^[2]