Ground, water and winter in Hanley Hills
Upland soils across mid-St. Louis County formed in loess, and the county soil survey names low strength and frost action as the limits for local roads, with adequate base material and drainage as the remedy. Clay under a driveway holds water, and freeze-thaw winters heave it. Base and grade do the real work.
When you compare bids, ask each contractor for three numbers in writing: the compacted asphalt thickness, the base depth, and what happens to the water. Those three decide how long the surface lasts.
Compacted asphaltTypically 2 to 3 in. for a car drive
Stone baseTypically 4 to 8 in., compacted
Drive on itUsually 2 to 3 days, longer in heat
First sealcoatTypically 6 to 12 months after paving
Typical ranges. Your Hanley Hills estimate is sized to the soil, the traffic and the drainage on your property.