3-Car Concrete Driveway & Drainage in Alexandria, VA | Professional Base Compaction

This Alexandria, Virginia homeowner wanted a three-car-wide concrete driveway. After inspecting the site we verified that the aggregate base under the old asphalt was over 6 inches thick and structurally sound, so we recompacted it to a high density and poured the new concrete directly on top instead of excavating and rebuilding the base.

Joints, drainage and the sprinklers

We maximized the parking footprint with a precision pour and a tightly cut control-joint pattern placed to align with the three parking stalls. Control joints are tooled (or saw-cut) at intervals set by the slab layout, and where a new slab meets any existing (cold) slab we isolate it with an expansion joint. For drainage we ran triple-wall underground piping for the gutter system with pop-up emitters, and graded the site so water moves away from the new driveway extension; we hard-pipe downspouts into the system using solid pipe so roof water does not saturate the yard. The existing sprinkler system was excavated and preserved without damage for the landscaper to reinstall.

How we normally build the base

When an existing base is not sound, our standard 4-inch driveway gets about 8 inches of excavation and about 4 inches of compacted #21A crushed stone, with 6x6 welded wire mesh pulled up into the center of the slab during the pour and a slip-resistant broom finish. A compacted stone base reduces, but cannot eliminate, the effects of clay movement (The Tuck Standard, Section 5F). Foot traffic is permitted after 24 to 48 hours, and vehicle traffic is prohibited for 7 days.