Roofing Materials. Roofing materials are very heavy. Make sure that when lifting heavy materials, always use your legs and not your back to avoid possible hernias. It is preferable to carry one bundle at a time to ensure safety up the ladder and on the roof instead of trying to move all of the materials in one trip. Try to store materials close to the roof to avoid having to walk long distances to retrieve new material each time. We hire a craning company to do our lifting to reduce the likelihood of injuries.