Gravel, Crushed Stone and Soil Delivery in Detroit, MI

From sandy loam down to limestone

The USDA soil survey maps the center point of ZIP 48201 as Urban land-Riverfront complex, dense substratum, on 0 to 4 percent slopes. Pavement and structures cover 80 percent of that unit. Riverfront soil, the native part, accounts for 19 percent.^[1]

Where Riverfront soil remains, its top mineral layer is a sandy loam that the survey rates well drained, in hydrologic group B with moderate infiltration. Linear extensibility in the top 100 cm comes in at 1.2 percent, a low value, so the soil holds its shape through wet and dry seasons. Sandy loam like this packs well and rarely needs heroic drainage work.^[1]

With four fifths of the map unit built over, the bigger unknown is fill. Old foundations, cinders, brick and broken concrete turn up in many urban yards, and that material can drain far worse than the sandy loam it covers. Dig a few test holes across any site before ordering stone, and plan to haul out anything soft or organic from under a drive or patio.^[1]

A dense layer, described by soil scientists as densic material, lies about 68 inches down at the center point. That depth sits well below most driveway and patio work, so it rarely affects a project, though it can slow drainage from a deep basement excavation.^[1]

Deeper still, the geologic map shows the Dundee Limestone, a Middle Devonian unit of limestone and dolostone. Bedrock of that kind sits far below the sandy soil and the fill above it, and garden or driveway work will not reach it.^[2]

The ground at the center point stands 620 feet above sea level on nearly flat terrain. Flat ground means water has little natural fall, so every gravel surface should get its own shallow crown or cross slope to keep puddles from forming.^[1],[3]

Frost and the gravel lot

The NOAA normals station at Detroit City AP, MI, about 5 miles away, averages 29.9 inches of precipitation a year and logs 112 days with a low of 32 F or colder. Its median last spring freeze is April 21, and the median first fall freeze is October 31.^[4]

That long run of cold nights tests every base. Water that gets into a gravel lot freezes, expands and lifts the stone, then leaves a soft pocket when it thaws. Over a winter, those pockets grow into potholes. The cure is drainage and density: a base that sheds water and is packed so tight that little can soak in.^[4]

For a parking lot or a long drive, lay fabric over the cleared subgrade, then pack Road Base or Crushed Concrete in thin lifts. Finish with Driveway Gravel or 3/4" Crushed Stone. A plow or snow shovel set slightly high leaves the stone in place, and a spring rake-out after the median last freeze of April 21 keeps the surface even.^[1],[4]

Downspouts, drains and a flat site

On a nearly flat site, water goes wherever the last grading left a dip. Before laying stone, check the fall with a string line or a long level and shape the subgrade so every surface slopes gently away from the building. A slope too small to see by eye is still enough to move rain off a gravel lot.^[1],[4]

Roof water should land on stone, not bare soil. A splash pad of River Rock under each downspout, or a short buried pipe that ends in a pit of Drain Rock, lets the sandy loam soak up the flow away from the foundation. Moderate infiltration in group B means a dry well of clean stone can take a good share of a storm when it sits in native soil rather than in compacted fill.^[1]

Paver patios fare well on sandy loam with low shrink-swell as long as the base drains. Pack Road Base in thin lifts over fabric, screed a thin bed of Concrete Sand, set the pavers and lock the edges. Pitch the finished surface away from the house, since frost lifts a patio that holds water.^[1],[4]

A backyard play area on sandy loam dries quickly when it is lined with Playground Sand or Wood Chips over a thin layer of stone. Mason Sand handles small leveling jobs and sets brick edging around a bed.^[1]

Side lots and new gardens

An empty side lot or a cleared yard can become a garden, but the soil on top may be fill rather than native sandy loam. Build raised beds and fill them with Garden Soil, or spread a thick layer of Topsoil blended with Compost over the old ground before planting. Imported soil gives vegetables a clean, known starting point.^[1]

Sandy loam drains fast and dries out in summer, so mulch every bed. Brown Shredded Mulch, Black Shredded Mulch or Wood Chips hold moisture, smother weeds and break down slowly into the soil. Wood Chips also make cheap, soft paths between rows that stay walkable after rain.^[1]

Plant tender crops after the median last spring freeze of April 21, and plan to harvest or cover them before the median first fall freeze at the end of October. A new lawn on a cleared lot does best with a thin layer of Topsoil raked level and seeded in late summer or early fall.^[4]

Choosing between Crushed Concrete and Asphalt Millings

Crushed Concrete and Asphalt Millings are both recycled materials that make a firm surface on a budget, and the choice depends on use. Crushed Concrete packs into a hard, light-gray layer that works as a base under other stone or as the finished surface of a work yard, a side lot or a farm lane. It drains reasonably well and holds up under heavy trucks.^[1]

Asphalt Millings are ground-up old pavement. Spread and rolled, they bind together as the sun warms them and traffic packs them down, giving a dark surface close to a paved feel. They shed water off the top rather than through it, so they need a crown, and they can soften slightly on a very hot day.^[1]

On well-drained sandy loam with many freezing nights, either material works over a packed base. Crushed Concrete suits a lot that will see equipment, while Asphalt Millings suit a residential drive or a parking area where a darker, quieter surface matters.^[1],[4]

Housing in ZIP 48201

The Census counts 10,273 housing units in ZIP 48201. Detached single-family houses make up 5 percent of them, and the median home dates from 1967. Owners live in 11 percent of the occupied units.^[5]

Detroit as a whole has 329,393 housing units, and 64 percent are detached houses. The citywide median build year is 1947.^[5]