Wrecking contractors may demolish roofing or crush autos. These licensed contractors are trained in demolition. Technicians are certified in use of explosives and scrap metal salvage. Professional wrecking contractors abide by safety procedures to keep workers and passersby out of danger. When you are considering a wrecking contractors for commercial demolition or excavation, research the company's safety record. Find the right company through referrals. Read about the wrecking contractor’s past work. Were customers satisfied about the time it took to complete the project? Select a company that belongs to a respected professional membership with annual audits for safety.