Gravel, Base and Soil Delivery in Irving, TX

Clay with a very high swell rating

The USDA soil survey maps the ZIP's center point as Ferris-Heiden complex, 5 to 12 percent slopes. The Ferris series makes up 65 percent of that map unit. Ferris is a soil of sloping ground, and its top mineral layer is clay.^[1]

Shrink-swell in the top 100 cm is rated very high, at 17 percent. Clay that rates this high can swell noticeably after a wet spell and crack open in a drought, with gaps wide enough to drop a pencil into. Anything rigid set straight on it, from a slab to a paver patio, rides those movements up and down.^[1]

The survey rates the soil well drained, which on a slope means water does not pond for long. It places Ferris in hydrologic soil group D, with very slow infiltration and high runoff. Rain mostly runs across the surface rather than soaking in, and the water that does get in swells the clay.^[1]

The survey lists densic bedrock at about 41 inches. That is a dense, compacted layer that roots and water struggle to pass through. Deep post holes or a deep drain trench may reach it.^[1]

Keep soil moisture near the house as even as you can. A steady drip line along a bed, with mulch over it, keeps the clay from swinging between soaked and bone dry.^[1]

Shale under the slope

The USGS geologic map places the center point on the Eagle Ford Formation, a Late Cretaceous unit of black shale, siltstone and limestone. Shale like this weathers into dark, sticky clay. Where a cut exposes it, the shale breaks into flaky pieces that soften when wet.^[2]

The map unit name gives slopes of 5 to 12 percent, which is enough of a grade to send runoff downhill with some speed. The ground at the center point stands 530 feet above sea level. On sloping clay, any stone surface needs firm edges and a plan for where the water goes at the bottom of the slope.^[1],[3]

When you dig into weathered shale and clay, the spoil is heavy and sticky when wet and rock hard when dry. Bring in Fill Dirt or Road Base for any area you need to build up, rather than trying to reuse the native clay as structural fill.^[2]

Storms on sloping clay

The NOAA normals station at Dallas FT Worth AP, TX, about 3 miles away, averages 37.0 inches of precipitation a year. Much of that can come in strong spring and fall storms that drop heavy rain in a short time. On clay with high runoff, that water picks up speed down a slope and can strip loose gravel off a path or drive.^[4]

Snow is rare at that station, averaging 1.6 inches a year. The same station logs 29 days a year when the low falls to 32 F or below. Light freezes rarely damage a well built base, but an ice storm on a sloping gravel drive can make it slick, so angular stone that grips is the safer top layer.^[4]

The median last spring freeze there falls on March 8. The median first fall freeze arrives on November 24. Planting and mulching fit comfortably into the long warm season between those dates.^[4]

Long dry spells between storms let the clay shrink and crack. Then a heavy rain pours into the cracks and swells the clay fast. Evening out those swings, with steady moisture near foundations and good drainage away from them, helps keep stone work and slabs level.^[1],[4]

Sloped lots benefit from terraces. Short retaining walls with a drainage layer of #57 Crushed Stone behind them break a long slope into level steps, and each step slows the runoff. Fill the terraces with Garden Soil or Topsoil for planting, and finish the paths between them with Walkway Gravel.^[1],[4]

Keeping patios and walks level on clay

The best defense on very high swell clay is a thick, compacted stone base that spreads the load and buffers the movement. Dig out the topsoil and the softest clay, compact the subgrade while it is slightly damp, and lay a woven geotextile fabric so clay does not work up into the stone.^[1]

Build the base from Road Base or Crushed Concrete in compacted lifts, thicker than you would use on sandy ground. Set pavers on a screeded bed of Concrete Sand, or finish a path with Stone Dust Screenings or Decomposed Granite compacted in thin layers. Slope every surface away from the house.^[1]

Keep water from collecting at the edges of a patio or walk, where it soaks into the clay and swells it. A border of Drain Rock or River Rock catches roof and patio runoff, and a French drain filled with Drain Rock can carry it down the slope to an outlet.^[1]

For posts, steps and small retaining walls, set the footings on firm compacted stone like #57 Crushed Stone rather than loose clay. A bed of clean stone drains and does not swell, so the footing moves less with the seasons.^[1]

Crushed Concrete or Road Base

Two base materials cover most jobs on this ground. Road Base is crushed stone blended with fines that compact into a hard, dense layer. Crushed Concrete is recycled concrete broken to a similar size, and it compacts nearly as firmly. Each one makes a stable layer between swelling clay and a surface.^[1],[2]

Crushed Concrete works well for drives, parking pads and shed floors where a plain gray look is fine. Road Base gives a more uniform blend and suits areas under pavers or a finished stone surface. Either one should go down in thin lifts, each wetted and compacted before the next.^[1]

For the top layer of a drive, Driveway Gravel or 3/4" Crushed Stone gives grip and drains rain off the surface. On a steep section, Asphalt Millings bind into a firmer surface that resists washing better than loose stone.^[4]

Fill under a slab, a shed or a raised patio should never be the sticky native clay. Fill Dirt brought in for the job compacts more evenly, and Fill Sand works where a layer must drain, such as under pavers or around a pipe.^[1]

Homes in 75038 and across Irving

The Census counts 15,632 housing units in ZIP 75038. Detached single-family houses make up 14 percent of them, so most homes are apartments, condos and townhomes.^[5]

The median home in ZIP 75038 was built in 1987. Owners occupy 20 percent of the occupied homes in the ZIP.^[5]

Irving as a whole holds 102,512 housing units, and detached houses make up 39 percent of them.^[5]

The citywide median build year is 1986.^[5]

The Texas transportation department sets its rules for the stone under its pavements as Flexible Base, Item 247, in the Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges (2024).^[6]