The coverage rate of driveway coatings is very important. If you don't use enough, you'll have untreated areas of the driveway. If you use too much applying a thick coat, the sealer will never "set up" or cure properly, and the excess may track into your home! The driveway must cure for at least 24 hours prior to car traffic (you can walk on it after a couple of hours on a nice day). It should cure overnight prior to applying a second coat of sealer or if very sunny/no humidity 2-4 hours before 2nd coat should be fine. For the warranty to be valid, a second coat is required on some of our sealer products. Refer to package for details.