Gravel, Sand and Soil Delivery in Suffolk, VA

Sandy banks on a steep map unit

The USDA soil survey maps Nansemond loamy fine sand, 15 to 30 percent slopes, at the ZIP's center point. The Nansemond series covers 80 percent of the map unit. A slope that steep on sandy soil is the kind of ground found along banks and the sides of ravines, where gravity and rain work together.^[1]

The top mineral layer is loamy fine sand, mostly fine sand grains with a little silt and clay. The survey rates the soil moderately well drained and places it in hydrologic group B, moderate infiltration. Rain soaks in readily on gentle ground, but on a steep face much of a heavy storm runs downhill before it can sink in, carrying loose sand with it.^[1]

Shrink-swell is low, at 1.5 percent. The sand does not swell or crack, so the risk on this ground is not movement from wetting and drying but erosion and slumping when water runs across a bare slope.^[1]

Before building on a steep sandy lot, walk it after a hard rain. Look for small gullies, fans of washed sand at the foot of the slope, and spots where water seeps out of the bank. Those signs show where runoff collects and where stone, mulch or a drain will do the most good. Fixing the path of the water first saves rebuilding the slope later.^[1]

Sand of the Tabb Formation

The geologic map places the Sedgefield Member of the Tabb Formation at the ZIP's center point, a Quaternary unit made of sand. These are young, loose coastal deposits, laid down by water and never hardened into rock.^[2]

Sand below sand means a dig rarely meets anything hard, which makes trenching and post holes easy. Loose sand also leaves the ground with little natural strength on a slope. Any structure set into a bank, from a step to a short wall, needs a compacted base and, on the steeper faces, a firm toe of stone to hold it in place.^[1],[2]

The ground at the center point stands 10 feet above sea level.^[3]

Loose sand also drains freely below the surface, so a dry well filled with Drain Rock can take roof water on the flatter parts of a lot. Keep it well back from the edge of a bank, though. Water released near the top of a sandy slope can seep out lower down and undercut the face.^[1],[2]

Rain, light snow and freeze dates at Lake Kilby

Weather averages come from the NOAA normals station at Suffolk Lake Kilby, VA, about 10 miles from the ZIP. It averages 51.8 inches of precipitation a year, a heavy total that tests every slope, ditch and drive.^[4]

The station averages 5.8 inches of snow a year and counts 56 days a year when the low reaches 32 F or colder. Freezing nights are common enough to loosen wet stone on a drive, though rarely hard enough to drive frost deep into sandy, well-drained ground.^[4]

At Suffolk Lake Kilby the median last spring freeze arrives on March 27, and the median first fall freeze arrives on November 15. Seed slopes and plant beds after the March date, and get a layer of mulch on bare soil before the November date.^[4]

Heavy rain falls on this ground in every season, and cold nights add their own wear. Water that soaks into a gravel surface during a storm and freezes that night can loosen the top stones. A crowned surface over a compacted, free-draining base dries faster and holds up better through both.^[4]

Holding a sandy slope

Bare sand on a 15 to 30 percent slope will wash in the first hard rain. The first rule is to keep it covered. Seed it, plant it, or blanket it with mulch, and keep foot traffic on a defined path. Wood Chips and Brown Shredded Mulch hold better on a slope than finer mulch, since the coarse pieces knit together and resist sliding.^[1],[4]

Where water concentrates, such as at the bottom of a downspout or along a path that runs downhill, line the channel with stone. Riprap set at the base of a bank breaks up fast water and stops it from undercutting the slope. River Rock lines smaller swales and looks natural. #57 Crushed Stone over fabric makes a firm, draining step tread.^[1]

For a terrace or a short retaining wall, set the first course of blocks on a compacted pad of Road Base, then backfill behind the wall with #57 Crushed Stone or Drain Rock wrapped in fabric. The stone lets water drain out instead of building pressure behind the wall, and the fabric keeps loose sand from washing through.^[1],[2]

Planting a slope works best in stages. Start at the bottom, set a row of shrubs or groundcover above the Riprap, and work upward, mulching each band as you go. Seed or plant after the March freeze date, when the soil is warming and spring rain helps new roots settle. Deep-rooted plants bind loose sand far better than turf alone.^[1],[4]

A driveway on loose sand

A drive on loamy fine sand needs binding and confinement. Strip the topsoil, compact the native sand, and lay woven fabric over it so the base does not sink. Build up Road Base in thin, wetted lifts, packing each one until it stops moving. Crushed Concrete makes a firm alternative.^[1]

Finish with 3/4" Crushed Stone or Driveway Gravel, and edge the drive on both sides so the stone does not spread. On any part of the drive that runs across a slope, add a shallow ditch of #57 Crushed Stone on the uphill side to catch runoff before it crosses the surface. With 51.8 inches of yearly rain at the station, a drive with no ditch and no crown will wash out at its low end.^[1],[4]

For a long drive that climbs a bank, consider breaking it into short, flatter runs with a water bar across the surface at each step. A water bar is a low, angled ridge of compacted stone that turns runoff off the drive and into a stone-lined ditch, so the water never builds enough speed to carve the surface.^[1],[4]

Homes in ZIP 23432 and the VDOT base standard

The Census counts 567 housing units in ZIP 23432. Suffolk as a whole holds 40,499 units.^[5]

Detached single-family houses make up 91 percent of homes in ZIP 23432, against 72 percent across Suffolk.^[5]

The median home in ZIP 23432 was built in 1986, and the Suffolk median is 1996. Owners live in 90 percent of the occupied homes in the ZIP.^[5]

The Virginia Department of Transportation names its base standard Aggregate Base Material, Type I, Size 21A, Section 208, in its Road and Bridge Specifications. It sets the grading for the stone layer under state roads.^[6]

Gravel Valet also delivers to Chesapeake, Norfolk and Newport News.^[6]