Pouring a concrete driveway step by step
Pouring a concrete driveway requires a great deal of coordination, because wet concrete begins to harden the moment it’s mixed.
Step 1: Establish Grade
The first step in installing a new driveway is to establish the desired grade. This is done well in advance of pouring concrete, using earthmoving equipment and hand tools to excavate, fill and compact the soil to the required specification. Then spread a layer of crushed rock. Local codes will dictate how much gravel is required to provide adequate support, drainage and protection from ground freeze.
Getting the forms right is the key to successfully pouring a concrete driveway, since the driveway will follow their exact shape and contour. Install forms to outline the driveway edges using 2×4, 2×6, and 2×8 lumber supported by 1×2, 1×4, or 2×4 stakes. Drive stakes at a minimum of 3 feet apart with additional stakes at curves where the concrete’s pressure against the form will be greater. Nail the form lumber to the stakes at least 2 inches above ground level keeping it level and straight. The stakes should be level with the lumber of a few inches below the top edge. Oil the form boards with old motor oil applied with a paintbrush. It will prevent the forms from sticking to the concrete and prevents water in the concrete from being absorbed by the forms, weakening the concrete mixture.
Step 2: Pouring concrete
Begin pouring concrete at the house, working toward the street. On many sites, a concrete pump will be needed to send the wet concrete to the starting point and prevent a heavy concrete truck from damaging the area or altering the grade.
Spread the concrete throughout the form using a long-handled tool with a straight metal blade that pushes or pulls wet mix into place. Try not to lift the concrete as you work it, as this puts a great deal of strain on your back. Work the concrete until it’s even with the top of the forms. Spreading concrete usually involves walking in the wet concrete, so be sure workers wear rubber boots.
When pouring concrete wet mix, you’ll work closely with the truck driver to direct and coordinate the flow. As you reach the end of the driveway form, there may be concrete remaining in the truck’s revolving drum. Have the driver pour any excess mix into wheelbarrows and keep it handy, using it as needed during screeding and leveling.
Step 3: Screeding
To level the concrete, called screeding or striking off, two or more people pull a long board or lightweight metal beam (wider than the driveway form, if possible) across the top of the concrete. Fill in low spots as you level using a shovelful of wet concrete.
The final leveling of the surface is done with a bull float. This tool’s handle is often 8 feet long or more to reach across the entire driveway, often from outside the form. Push the bull float away from you with the weight on the back edge of the tool to smooth the surface. Then twist the handle, shifting the pressure to the front edge of the blade, and pull the float back toward you. Check the blade before beginning and periodically throughout the process, removing any concrete.
When pouring concrete from the chute, you’ll work closely with the truck’s driver to direct and coordinate the flow. As you reach the end of the driveway form, there may be concrete remaining in the truck’s revolving drum. You’ve paid for all of the concrete in the drum; once the truck rolls away, that concrete is gone. Most crews pour excess mix into wheelbarrows and keep it handy, using it as needed during screeding and leveling.
Step 4: Finishing the concrete
Within hours of pouring concrete, you can apply any final touches. Work the surface with a hand trowel to smooth out any imperfections. Slide an edging tool back and forth between the lumber and the hardening mix to create a rounded edge.
Concrete, by its very nature, will eventually crack during freeze-thaw cycles. Use a groover against a straightedge to create control joints. A control joint is a groove placed in a concrete surface, similar to the way a piece of glass is scored before cutting. A control joint encourages the concrete to crack on the underside of the control joint where it won’t be visible in the finished driveway. Control joints should be positioned to run across the concrete surface every 8 to 12 feet, and wherever the driveway meets a sidewalk or existing concrete slab.
To improve appearance and traction, many driveways have a textured finish added to the concrete. For a heavy swirl pattern, use a wood float instead of a trowel and work while the concrete is still fairly wet. For a soft pattern of parallel lines, drag a soft brush or broom straight across the moderately wet surface.
After pouring a concrete driveway, keep all vehicles, machinery, and foot traffic off of the finished driveway for at least 72 hours to allow the concrete to fully cure.
‒By Todd Brock