Plumbers specialize in assembling, maintaining, and repairing pipes and systems for gas or water distribution in residential or commercial buildings. They are also responsible for troubleshooting, diagnosing, and testing plumbing and drainage systems. Duties include meeting with customers at their homes or business to perform customer-requested work orders, preventative maintenance, and emergency repairs. Using hand and power tools, they complete installations of gas and water supply, pipe systems, and various plumbing fixtures, including faucets, toilets, and bathtubs. Plumbers earn certification through either a community college, technical or trade school and gain years of experience through an apprenticeship with a master plumber to obtain their plumbing license. They use a company truck to visit job sites and work full-time with the opportunity for overtime.