To become a skilled roofer training is essential. It can be acquired informally through"learning-by-working;" through company on-the-job training programs; by attending trade or vocational/technical schools; through unilaterally (management or labor) sponsored trainee programs; through registered labor-management apprenticeship programs, or a combination of the above. It is generally accepted that the more formalized training programs give more comprehensive skill training. Recommended high school courses include mathematics, blueprint reading, and general shop.