Concrete expansion joint sealer fully cures in three to five days. Although the sealer feels dry to the touch in only one to two hours, waiting a full five days before driving on it ensures that the sealer stays in place.
Apply concrete expansion joint sealer when no rain is expected for 24 hours and the temperature is between 40 and 100 degrees Fahrenheit. Completely removing old sealer and filler is essential preparation before applying new sealer. Foam backer rods form a base layer under the sealer in larger compression joints. The joint sealer goes on top of the rods to provide a final protective layer to keep moisture and debris out of the joint.