Bulk Gravel, Rock and Soil Delivery in Davenport, IA

Ground that has been built over

The USDA soil survey maps the center point of ZIP 52801 as Urban land, with 100 percent of the map unit paved or built over. On ground like this, what lies under a yard is usually old fill, broken stone, cinders or soil brought in when the block was first graded, and it can change from one side of a lot to the other.^[1]

The practical rule is to dig a test hole before you plan any base. If the shovel turns up firm, mixed fill, it can usually be compacted and built on. If it turns up soft, dark, wet material, take it out and replace it with Fill Dirt or Fill Sand compacted in layers. Fill Sand drains freely and is the easier of the two to compact by hand, while Fill Dirt holds its shape better when you need to raise a low corner and then plant on top.^[1]

The ground at the mapped point lies 560 feet above sea level. For a paved-over center like this one, how water moves across each lot depends on the grading that was done there, so look at where puddles form after a rain and plan any stone work to move water toward the street or a drain rather than toward a wall.^[2]

A station with 118 freezing days a year

Weather normals come from the NOAA station at Rock Island L&D 15, IL, right beside the ZIP. That station averages 38.8 inches of precipitation a year, enough for steady rain through the warm months and snow or freezing rain in the cold ones.^[3]

The Rock Island station counts 118 days a year when the low drops to 32 F or colder. Each freeze turns water in the ground to ice, and ice takes up more room than water, so soil that stays wet through a cold snap lifts and then drops again as it thaws. That cycle is what pushes up pavers, cracks slabs and opens potholes in a weak gravel drive.^[3]

The median last spring freeze at the station is April 19. The median first fall freeze is October 22. Bed planting, seeding and most base work fit best between those two dates, while ground that is still frozen should not be compacted or built on.^[3]

A base that stands up to frost

The answer to frost heave is a base that drains. Water that cannot stay in the stone cannot freeze in it. Under a parking pad or a walk, dig past the loose surface fill and compact what lies below, then lay fabric if the bottom of the hole is soft or full of fine soil.^[3]

Build the base with Road Base or Crushed Concrete in thin, compacted lifts. Road Base and Crushed Concrete are each angular and well graded, so they lock into a firm layer. For a pad that floods in spring melt, put a layer of #57 Crushed Stone or 1-1/2" Crushed Gravel under the Road Base. Open, clean stone like that holds no fines and gives meltwater an easy path out from under the pad.^[1]

Top the pad with 3/4" Crushed Stone or Driveway Gravel. After the median last freeze of April 19, walk the surface and rake any stone that the plow pushed onto the grass back into place, then roll it to settle the top. Asphalt Millings make a firm alternative for a pad that gets plowed, as they bind together and shift less under a blade.^[3]

Snow pushed to the edge of a pad melts on mild afternoons and freezes again overnight, so the edges of a gravel surface go through more freeze and thaw than the middle. A border strip of Drain Rock along the side where the shovel piles snow gives that melt a quick way down before it can soak back into the base.^[3]

Planters and beds where the ground is paved

Where the native soil has been paved or buried, planting means building up instead of digging down. Raised beds and large planters filled with Garden Soil give roots clean, loose ground that drains, and they warm earlier in spring than the compacted fill around them.^[1]

For an in-ground bed, loosen the top layer and blend in Compost and Topsoil until it crumbles in your hand. Cover it with Brown Shredded Mulch or Black Shredded Mulch after planting. With a median first fall freeze of October 22, a fresh layer of mulch in late fall also insulates perennials and keeps the soil from heaving as it freezes and thaws.^[3]

Along walls and foundations, a strip of River Rock or #57 Crushed Stone over fabric keeps rain from splashing soil onto siding and lets water soak in away from the wall. Pea Gravel works well for narrow side paths between buildings, since it drains well and is easy to rake smooth.^[3]

Pea Gravel or #57 Crushed Stone for a walkway

For a path between a back door and a garage, the usual debate is round Pea Gravel against angular #57 Crushed Stone. With 118 days a year at or below freezing at the Rock Island station, the deciding question is what happens to the path in winter. Pea Gravel is smooth and comfortable underfoot, and it drains well, but its rounded stones roll when a shovel scrapes across them and end up in the lawn by spring.^[3]

Angular #57 Crushed Stone locks together and stays put under a shovel, and its open gaps let meltwater fall straight through, so the path does not turn into a slab of ice after a thaw. It is less comfortable in bare feet. Over the mixed fill found on built-over ground, either stone needs a compacted layer of Road Base under it and an edge to hold it in place. In the end, Pea Gravel suits a garden path that sees little winter use, and #57 Crushed Stone suits the walk you shovel every snowy morning.^[1],[3]

A third choice is 3/8" Crushed Stone, which is small enough to walk on comfortably and angular enough to stay put. Lay any new path after the median last freeze of April 19, when the ground has thawed and can be compacted properly.^[3]

Housing in ZIP 52801 next to Davenport

The Census counts 1,257 housing units in ZIP 52801, and detached single-family houses make up only 4 percent of them. The median home in the ZIP was built in 1961.^[4]

Davenport as a whole holds 46,849 housing units, 64 percent of them detached houses, with a median build year of 1967. With few detached houses in the ZIP itself, many orders here are for shared lots, courtyards, alley parking and planter boxes, where a few yards of stone or soil go a long way.^[4]

Around older buildings, a gravel parking area may already have a sound base hidden under a thin, worn surface, and a top-up of 3/4" Crushed Stone can be all it needs. Dig a small test spot before ordering to see how deep the old stone runs and whether it still feels firm under a heel.^[4]