Installing a Concrete Curb Lay out the site, including the width of the concrete curbs, and excavate it to the depth codes require. Install the staked forms and spread and tamp the gravel subbase. Pour the concrete, screed it on the forms, and finish the edge. When the concrete has cured, remove the forms, lay the sand and paving, and backfill the trench. Remember that you can color, texture and curve the concrete.