10-gauge wire mesh, #4/#5 rebar, and form lumber—what to use, when to use it, and where to get it fast in Chicagoland If you pour concrete in the Chicago area, you already know the difference between a clean pour and a callback usually comes down to three things : the right reinforcement, proper placement, and forms that stay straight. At A&A Equipment & Supply , we’re stocking the everyday flatwork materials concrete crews ask for— 10-gauge welded wire mesh, #4 and #5 rebar,