Odds of Hanging On
To be a successful roofer, you need to know how to balance your abilities with clients' expectations. Believe it or not, contractors don't always have stellar reputations. This is usually either because they try to do too much at once and get overloaded, or because they promise everything by a certain date and then change their mind. Neither way is a good way to keep your customers happy.
Balance in all things is good, especially if you're a roofer. If you develop a reputation for doing good work in a reasonable time frame, you'll hang on as long as you want.