A new black top surface will last anywhere from 25 to 30 years. But there are two main factors involved. First, proper installation must be done correctly the first time. The application thickness will vary from 2 1/2 to 3 1/2 inches thick on a base surface. Secondly, you must continue to keep your black top seal coated. Depending on your location and weather every 1 to 3 years. But you WILL NOT get 25 to 30 years from black top if it is not maintained OFTEN OR INSTALLED RIGHT. But chip seal will last on top of a good base for 15 to 20 years with no maintenance work involved. You can drive heavy loads and traffic on chip seal without it cracking or breaking up. That is not always the case with black top jobs.