Gravel, Rock and Soil Delivery in Edmond, OK

Swelling silt loam above the Fairmont Shale

The map unit at the ZIP's center point is the Renthin-Urban land complex, 1 to 5 percent slopes. The Renthin series makes up 55 percent of it, and 45 percent is mapped as urban land, ground that has been paved or built on. Its top mineral layer is silt loam, a fine, smooth soil that turns slick when wet.^[1]

Shrink-swell in the top 100 cm rates high, at 7.5 percent linear extensibility. That is the strongest warning on the soil report. Clay-rich ground with a rating like this swells after rain and shrinks hard in dry spells, and the movement can heave a slab, crack a footing or roll a paver edge out of line.^[1]

Paralithic bedrock, a soft rock that a shovel can still scrape, lies at about 58 inches. The mapped geologic unit is the Fairmont Shale, a Permian bed of shale and siltstone. Weathered shale breaks into flakes and clay, which fits the high swell rating near the surface.^[1],[2]

The survey calls the Renthin soil well drained, yet it places the point in hydrologic group D, the class for very slow infiltration and high runoff. Water moves down through the profile in time, but a heavy storm mostly runs across the surface first. Expect puddles on flat spots and fast sheets of water down any slope.^[1]

The ground at the center point stands 1,180 feet above sea level, with slopes of 1 to 5 percent in the map unit. Even a gentle grade carries runoff downhill toward the lowest edge of a yard. Plan the low side of any project first, since that is where water will gather.^[1],[3]

Guthrie 5S rain, snow and freezes

The nearest NOAA normals station is Guthrie 5S, OK, about 12 miles away. It averages 38.2 inches of precipitation and 7.1 inches of snow each year. On swelling silt loam, that rain is what drives the soil to grow and shrink, so keeping water away from a slab edge does as much good as any stone.^[4]

Guthrie 5S logs 87 days a year when the low drops to 32 F or colder. Water that soaks into a base and then freezes expands and loosens the stone, so a base that drains fast survives winter better than one that holds water.^[4]

The median last spring freeze at that station falls on April 10. The median first fall freeze comes on October 28. Seed lawns and set tender plants after the spring date, and lay fresh mulch before the fall date to shield roots from the first hard nights.^[4]

A drive that rides out swelling clay

On high-swell silt loam, depth and drainage protect a drive. Dig out the top layer of soft soil, shape the subgrade with a crown, and cover it with a woven geotextile. The fabric stops wet fines from squeezing up into the stone and keeps the base clean for years.^[1]

Lay a coarse first course of 1-1/2" Crushed Gravel or #4 Crushed Stone to bridge soft spots. Cover it with Road Base in thin lifts, each one compacted hard. Top the drive with 3/4" Crushed Stone or Driveway Gravel. A thick, layered base flexes as the clay moves and settles back, where a thin one cracks into ruts.^[1]

Cut a shallow ditch along the low side and fill it with Drain Rock, wrapped in fabric. On group D ground, the ditch carries water away instead of waiting for it to soak in. Keep downspouts aimed into the stone, never onto the drive itself.^[1]

Edmond houses by the numbers

ZIP 73003 holds 10,019 housing units in the Census count. Detached single-family homes are 75 percent of that stock. The median home in the ZIP dates from 1995. Owners live in 58 percent of the occupied homes.^[5]

Across Edmond the Census counts 39,841 housing units, and 78 percent are detached houses. The city's median build year is 1993.^[5]

The Oklahoma Department of Transportation sets its own requirements for the stone layer under state roads, called Aggregate Base, Type A, in Section 303 of the Standard Specifications for Highway Construction (2019). That book governs highway work.^[6]

With three of every four homes in ZIP 73003 detached, the usual project is a single-family yard: a side parking pad for a trailer, a widened drive, a backyard patio or a row of new beds along a fence. A house built around the ZIP's median year of 1995 may have its first drive and walk wearing thin by now, and a refresh with new base and top stone is a common request.^[5]

Beds and paths on slick silt

Silt loam crusts after rain and can seal the surface of a bed. Work Compost into the top few inches, or build raised beds with Garden Soil, so roots get air and water soaks in. A layer of Black Shredded Mulch or Wood Chips keeps the crust from forming and slows runoff on group D ground.^[1]

Garden paths stay firm with Stone Dust Screenings or Decomposed Granite packed over fabric. Pea Gravel and Walkway Gravel feel softer but need an edge to keep them in place. With high shrink-swell below, a flexible path beats a poured walk that cracks.^[1]

Keeping water away from a foundation

On soil that swells as much as Renthin silt loam, the strip of ground right beside a house needs the most care. When that strip soaks and then dries, the soil under one side of a slab moves while the rest stays put. The goal is steady moisture: no flooding after storms and no deep cracks in a drought. Gutters and downspouts do half the work, and the material around the house does the rest.^[1]

Grade the soil so it falls away from the wall for several feet, using Fill Dirt to build up low spots and compacting it well. Cover the strip with fabric and a layer of River Rock or #57 Crushed Stone. Stone lets the surface dry between rains and stops splash from wetting the siding. Run each downspout into a buried pipe or a trench of Drain Rock that ends well out in the yard, never into a pit right by the footing. On group D ground, a pit near the house just holds water against the clay.^[1]

Plant beds near a foundation still work if they drain well. Keep thirsty shrubs a few steps out from the wall, use Garden Soil only in the top layer, and mulch with Brown Shredded Mulch so the soil stays evenly damp instead of swinging between wet and dry.^[1]