How do I Expand Concrete Driveways?

Measure the area for expansion and hammer wood stakes into the ground to mark the site.

Dig the area between the stakes down 8 inches with a shovel.

Level the base of the excavation by knocking down high spots and filling in low spots with the shovel.

Tamp the base of the excavation with a hand tamper or gas powered tamper to compact and level the soil.

Measure the thickness of the existing concrete driveway, and mark the halfway point along the entire length of the edge.

Mark off 3-foot increments along the length of the exposed edge of the existing driveway.

Use a 3/4-inch masonry drill bit to drill 6-inch deep holes into the side of the existing driveway at each previously marked 3-foot increment.

Brush the inside of the holes with a round wire brush to remove bits and pieces of concrete.

Mix an epoxy-based grout according to package directions and pour into a grout bag.

Insert the tip of the grout bag into the hole in the edge of the existing driveway and fill the hole.

Insert an 18-inch long, 5/8-inch piece of rebar into the hole and force it as far as possible. Repeat for each hole. The rebar will anchor the new driveway to the existing driveway and stop the new driveway from shifting away.

Add 4 inches of crushed stone to the base of the excavation.

Level the stone by sweeping a long board over the top to knock down hills and fill in valleys.

Place 2-by-4 pieces of lumber around the excavation end-to-end to create a form, except for the side with the existing driveway.

Lay 1-by-4 pieces of lumber, standing on the 1-inch end every 6 feet across the crushed stone, touching the form on one end and ending 1/2-inch away from the existing driveway. These will act as expansion joints, which will prevent cracking in the future.

Lay heavyweight wire mesh over the crushed stone.

Place foam backer rod along the edge and at the same height as the surface of the existing driveway. Foam backer rod acts as an expansion joint between old and new concrete.

Schedule a 4,000-PSI concrete pour from a ready-mix concrete company. PSI, pounds per inch, refers to the amount of weight concrete handles without breaking.

Pour the concrete over the top of the crushed stone, wire mesh and exposed rebar up to the height of the existing driveway.

Smooth and level the surface of the concrete with a bull-float, which is a trowel on the end of a long pole.

Spray the surface of the concrete with curing compound and allow the concrete to set.