Roofing contractors don & usually need formal education, but they need on-the-job experience to discover their trade. While each state has different licensing rules, many require a roofer to have at least two years of experience before they can become licensed. These professionals also need liability insurance coverage, to be bonded and to have a company license. HomeAdvisor can help you discover the ideal roofer for your project. While each state has various licensing rules, the majority of require a roofing contractor to have at least 2 years of experience before they can become certified. These professionals also require liability insurance, to be bonded and to have a company license.